A FM needs training help too tl;dr: How to visualize and assess if you can't?
I'm pining, no, not for the fjords, but for returning to the board after Corona. I still read a good amount of chess books, but maybe some specific training couldn't hurt in the meantime.
Not surprisingly, as a FM I exactly know my weaknesses:

1 ageing (I'm 60 now)
2 no knowledge of opening theory
3 a certain shortcoming when dealing with pin tactics
4 horizon effect

When dealing with that...

1 I'm currently going for my diploma in computer science, so probably my brain's still flashing like it did when I was young (ha, Rolling Stones reference). Nothing specific I could do anyway except constant practice.
2 Remembering and playing main variants would take the fun out of chess for me (and it's even doubtful if it increases my score - what good is it losing 25% less by opening desasters when drawing 50% more?).
3 This could be easily trained specifically, e.g. with a Lichess pin themed training set.
4 This is what I am asking for (but feel free to comment on the other points). It seems I always calculate (when I calculate at all, my intuition is extremely good, i.e. I quickly see the candidate move if there is only one) exactly one move too short. (And that is when the figures begin to blur before my mental eye. I'm a very lousy "blindfold" player by the way.) For example, if the problem involves trampling the poor king to death with Q and R, the calculation tree forks to kingdom come and I am unable to follow it.

Thus: How to decide when one can cut a variant with a definite result? And don't just answer "quiet"!
A prime recent example (donated to me by a chess club colleague as a tactic problem for our club zine:
[fen ""]

1.e4 e5 2.Nf3 d6 3.d4 Bg4 4.dxe5 Bxf3 5.Qxf3 dxe5 6.Bc4 Nf6 7.Qb3 Qe7 8.f3 Nc6 9.O-O Qc5+ 10.Be3 Qe7 11.Nc3 Nd4 12.Qa4+ c6 13.Rad1 b5

Of course, I start calculating Nxb5 in a microsecond (no FM needed for that...). Hack, hack, hack, slice and dice, rook doubling, oh bother, Black can protect the mobbing victim on d7 sufficiently. Quiet. Cut. (Of course I'd play it anyway as the piece would be lost in any variant, but also of course I must already decide about that when playing Rad1.)
A check on Lichess with Stockfish shows Black is dead as a doornail: the position is quiet for one, two moves, but even if White could not play B-xa7-b6, Black would take ages to untie while White simply promotes one of the queenside pawns. Thus, again: how can I "see" that, even if I'm more or less unable to actually "see" the position before my wrong cut?

I'm not that old (yet), but I do know how it feels. I even showed a few of my games to GMs asking for feedback, and it turns out that very often I have seen the (good) move recommended by them, pondered about it, but could not calculate properly and played another move instead. Too bad.
The solution I came up with is largely based on Dvoretsky books (not the latest ones but those from maybe 80-s or 90-s): calculation is overrated. Calculating is for engines; for humans it is very inefficient in terms of energy consumption and error costs. Instead, you should avoid calculating as much as possible, and only do it when absolutely necessary. With your experience, you should trust your intuition and know which move is good and which not before starting to calculate lines. In your example, you already knew that Nxb5 was the move; there was no need to calculate it before you actually had the position after Qxb5+ Nd7. Dvoretsky actually has quite a few examples how to solve studies using this method.
This is not going to be a popular opinion due to the recent progress of engines chess; a lot of noobs will think that if computers play better than humans, they should try thinking just like engines do. I suppose if you're 15 this might indeed work for you.


How to calculate the number of combinations for Chess960 positions Can someone derive how do we get the total number of 960 possible positions for Chess960?

You're counting the same position a couple of times and not including the rule that the bishops have to be on opposite colors.  (And possible that the king must be between the rooks.)

The actual number is 4 x 4 x (6 x 5) / 2 x 4

4 for the LSB

4 for the DSB

(6 x 5) / 2 for the two knights (halved due to account for the same type of piece being placed)

4 for the queen

1 due to the king must be between the rooks  (Without this rule, it would be (3 x 2) / 2 or 1440.)


When are pieces worth more (or less) than their nominal value? Which are the most common situations in which pieces are worth more/less than their value, in point?

For example, I know that a protected Knight on 6th rank (3rd for Black) of columns d and e may be worth at least as much as a Rook (thus 5 points). The same for a very strong fianchettoed Bishop.  Another example: a Rook on 7th rank (2nd for Black) usually is worth a Pawn more than its normal value, while 2 Rooks there may be worth 3 Pawns more than their normal combined value (if opponent's King stays on 8th or 1st row respectively, of course).

Are there other similar situations?

While I don't think it's reasonable to list every noteworthy situation, here are a few more that will probably be good general guidelines.  You can use rules-of-thumb like this in order to evaluate material imbalances in your own games:

the bishop pair may be worth a rook and two pawns
the bishop pair and a pawn is worth a knight and a rook
a knight on the 6th rank is worth a rook if it cannot be traded off or chased away (and it is close to the action)
an unopposed dark square bishop is worth a rook if the opponent has played g6 and the queens are on the board
a rook on the 7th is worth an extra pawn
doubled rooks on the 7th is usually good for at least a draw
the queen may be worth two rooks if the side with the queen can start an attack.
three minor pieces may be worth a queen - take this with a large grain of salt, in every position, one side or the other usually has a decisive advantage so each case must be carefully considered
a minor piece, a rook, and a pawn are sometimes worth a queen
however, the queen with a pawn is usually stronger than two knights and a rook (for some reason, the knights just don't coordinate well, I've never had this situation in my own games)
three pawns are worth more than a piece in the endgame but much less than a piece in the middlegame (unless they are advanced in which case they restrict the opponent)

Those are all of the strange imbalances I can think of off the top of my head.  I omitted things like rook and pawn vs two pieces or knight vs bishop because those are fairly common, and those especially depend on the position.  Again, every position needs to be considered on its own, this is just to get you in the right frame of mind when you have to make a determination.


Is the game done if your only movement is getting out of check? If I play as White and use my queen to check Black on every move, and Black can only move their king to get out of the check, can I win the game?  White could move something else, but they decide to check on every move.

This happened years ago when I was new to the game in a tournament, and the referee gave me the win as it was not checkmate, but my opponent only had a king and two pawns left. Was that my win?

No, this is not a win.

What you describe is called perpetual check and according to the rules of chess it results in a draw.


Carlsen beat a high ranking GM with 1 Nh3. Conclusions? In 2018, Magnus Carlsen played a rapid game on chess.com agaisnt Grandmaster Aleksey Dreev in which his opening move was 1. Nh3.

[Title "Magnus Carlsen-Alexey Dreev, Pro Chess League, chess.com INT, 2/24/2018"]
[FEN ""]

1. Nh3 Nh6 2. f4 d5 3. Nf2 Ng4 4. e3 Nxf2 5. Kxf2 c5 6. b3 Nc6 7. Bb5 Bd7 8. Bb2 a6 9. Bd3 Qc7 10. Nc3 e6 11. Qh5 Be7 12. Rhf1 Bf6 13. Kg1 Nb4 14. Rac1 Nxa2 15. Rce1 Nb4 16. f5 e5 17. e4 c4 18. Nxd5 Nxd5 19. Bxc4 Nb4 20. c3 Nc6 21. Qxf7+ Kd8 22. Ba3 Be8 23. Qd5+ Qd7 24. Bd6 Be7 25. Bxe7+ Kxe7 26. Qc5+ Qd6 27. Qb6 Bd7 28. d4 Nd8 29. Qa5 Nc6 30. Qa2 Kd8 31. Rd1 Kc7 32. Qf2 Rad8 33. b4 Rhf8 34. b5 axb5 35. Bxb5 g6 36. f6 Kb8 37. Bc4 Bc8 38. Bd5 Be6 39. Bxe6 Qxe6 40. d5 Qd6 41. Ra1 Kc7 42. dxc6 Qxc6 43. Ra5 Kb8 44. Qa7+

Does that prove that opening Nh3 is sound, or was it just a psychological play to take a slightly weaker player out of the book? Does it show that Carlsen is that much better because he can get away with such moves?

It was one game in online rapid. You cannot deduce from one game that 1.Nh3 is sound or not sound. Carlsen was actually MUCH worse out of the opening, and just outplayed Dreev later. It really means nothing other than Carlsen is currently much stronger.

Most likely 1.Nh3 is not good, and this is unusual for a first move: Stockfish already evals this as -.62 at a depth of 50.


Resigning (Inevitable Checkmate) I am a relative beginner to chess but have noticed particularly playing online a lot of players will resign if they lose a strong piece, for example, their queen.

Is this sportsman like? I wouldn't have thought so, but I read a thread on here that stated stronger players will resign if a checkmate is inevitable. I can only assume resigning has less of an impact on rating.

Yes, resigning a clearly lost game is indeed considered good behaviour. Sometimes not resigning is considered unsportsmanlike!

It makes no difference on the result of the game whether you resign, are checkmated, or lose on time - a loss is a loss. In any rating system I've ever heard of, the method of losing doesn't make a difference.

It's just that people don't like wasting time when they're 100 % sure that their opponent will win the game almost effortlessly with no danger of making a serious blunder.


Bronstein's lines of attack on the chessboard I remember reading as a child in a book by David Bronstein about an interesting piece of advice that he gave. He recommended to imagine the lines of movement for each piece all across the board as if not restrained by any intervening pieces. This is supposed to help to see all the tactical possibilities.

My question is to help me locate this quotation. I am also interested in any kind of remarks concerning this piece of advice.

This is actually a common piece of advice given to students of chess. Often chess blindness begins with not projecting your piece movement abilities beyond the first encountered piece in it's way. this helps to clear that deficiency away and begin to cultivate imagination and fantasy position ideas in your mind.


How do I make arrows and colored squares using Chesstempo's viewer? I am using Anki to study chess. I use Chesstempo's viewer. My question is: How can I make arrows and squares with color on the board?

I do not think that it is currently possible. Here is a list of features, and while a couple are close, that looks like a future enhancement. Here is a link to the original source.

Features in current version

Multiple games per PGN file
Multiple boards per page
PGN comments/annotations
Recursive Annotation Variations (i.e. alternative lines)
FEN tag supported for arbitrary starting positions
Support for subset of Numerical Annotation Glyphs (NAGs, e.g. ? !?)
Multiple board size and piece styles
Option for automatically playing through all game moves
Alternative move display formats
CSS controlled layout
Animated piece moves
Optional Row and column labels
Drag and drop piece moves (to make next move in game)
**Optional Highlighting of from/to squares
Optional Highlighting of valid squares when dragging pieces**
Display of taken pieces
Read moves from PGN file on server or embed PGN directly into webpage

Features to be added in future versions

Crosstable support
**Visual hints such as move direction arrows etc**
Record moves mode with PGN output
Allow embedded board snapshots in move display
Configurable Board flipping (current version auto-flips if first mover is black).


Placing the bishops on the right square I have always been curious about how I can determine whether the bishop is better on e7 or on d6 playing with Black (of course when c5 and b4 are not possible or satisfactory).
I will provide some games of mine:

For instance, in this position the bishop has to retreat either to e7 or d6. The difference in the valoration is not huge but the bishop on e7 has a greater advantage for black (0.7) whereas on d6, where I think the bishop is more active as it controls the central square e5, the computer says Black only has an advantage of 0.4.

In this postion which is more similar to the point I am referring to, Black can choose both of the squares but putting the bishop on e7 is slightly better.

All I want to know is what is the nuance between them that makes the assessment of the positon vary a little. I have provided these two games but I would really appreciate advices for ANY similar situation regarding the squares e7 and d6.

In both diagrams, the bishop is better on e7, because the d-file is likely to become an open file, and the bishop would block the rook's activity.

The first example has the future activity of the bishop to consider.  As the bishop isn't going to exchange on f4 or needed to protect an e5 push, its activity will have to come after moving to f6.  Here it will exert pressure on white's queen side.

The second example has breaking the pin as a consideration.  Without the bishop on e7, the queen would be tied to the defense of the f6-knight.  If the pin remained, Ne5 would be a strong move as the capture is now more dangerous--providing another attacker upon f6.

As a general rule, the more squares the bishop can attack on the opponent's half of the board, the more active it becomes.  However, especially as black, the more passively placed king's bishop is needed for other reasons, mostly defensive needs.


What is meant by openings with lot of theory versus those with little or none? I just started playing chess one week ago. I've done a bit of reading but can't find anything that explains what is meant by openings with a lot of theory versus ones with a little or no theory. Can this be explained in
a "chess for dummies " language?

In chess, "opening theory" or just "theory" means "established opening lines": usually lines that have been studied and judged to lead to more or less equal positions, and appear in books.
It's unfortunate terminology since it matches neither the day-to-day meaning of the word (something that's contrasted to practice) nor the meaning used in game theory. But we're stuck with it.
While "opening" sometimes refers to a specific line, it's better to think of it as a game tree, that is, a collection of lines with a common origin. Openings with "lots of theory" are those with large game trees. This is usually a combination of two factors: long lines (the tree is deep) and lots of variations (the tree is wide, with a lot of branches).
Openings that are popular among top players will be studied more so will tend to have longer book lines. Openings that lead to positions with a lot of good moves will have lots of variations, while openings with forced moves will naturally have fewer variations.
In short, openings with lots of theory are those with more pages in opening books.
For example, Mastering the Chess Openings devotes 75 pages to the Sicilian Opening, and only 10 to the Caro-Kann. So we could say that the Sicilian has more theory than the Caro-Kann. Of course, different books will give you different numbers, but you get the idea.


How to Win King vs Pawn in this Situation I read from this website (example 2) that you can win the game in the following situation:

[Title "Black to move - Black's POV"]
[fen "8/8/8/5PK1/1r1k4/8/8/8 b - - 0 59"]

I play as black. I want to keep the rook and king to win the game, and prevent him from queening. I can't let my rook be captured.

But he doesn't finish the game. He just says "And in this position you'll always be able to win the pawn and the game." But I don't see how I can intrude with my king to the queening square.

How can this game play out?

You don't necessarily have to intrude with your king to the queening square.
You really need 3 things -

Get the king close to the pawn
Control the pawn's advancing square with both pieces
Capture the pawn

So, in this case,
Ke5 followed by Rf4 will achieve steps 1 and 2. Then you can capture the pawn and win.

So, for e.g.
1... Ke5
2. f6 Rf4
3. Kg6 Rxf6+


Is there any hope left for Black? 7b/p3R3/k6r/N7/KP6/8/8/8 b - - 3 41

I got into this endgame in a Alkehine Defense game against a FM. The engine evaluates it as +0.6 .

But all I can see is that any inaccuracy on Black’s part leads to a loss. Is there a way to force a draw?

The bad news is, there is no way for black to force a draw in this position. However, with a few precise moves, you can enter a number of simpler endgames that are theoretically a draw and not too hard to defend. Let me illustrate that with a few sample variations. 1. ... Rb6 Preventing b5. Now, white has 3 main options, apart from just waiting. 2.Nb3 (2.Rf7 would be a normal waiting move. Now, we can enter an endgame of rook vs bishop by force: 2. ... Bc3 3.Nc6 Rxc6 4.b5+ Kb6 5.bxc6 Kxc6 =; 2.Nc4 Rb8 again, we threaten Bc3 3.Re6+ Kb7 4.Na5+ Ka8 5.Nc6 Rc8 6.Kb5 Kb7 and Black can hold. Checks are always blocked from the side and white cannot make any progress; 2.Nc6 enters the bishop versus rook endgame we saw above: 2. ... Rxc6 3.b5+ Kb6 4.bxc6 Kxc6 5.Rxa7 =) 2. ... Rd6 this forces white to either enter an endgame of rook + knight vs rook or accept that black will achieve a comfortable holding position 3.Re8 the most ambitious (3.Nc5+ Kb6 4.Rb7+ Kc6 5.Rxa7 Bd4 6.Ra6+ Kd5 7.Ra5 Kc6 8.Nb3 Bb6 once black has gotten his bishop to the a7-g1 diagonal, he should be fine. If white ever tries to push the pawn, black can, in the worst case, sacrifice his bishop and liquidate into a theoretically drawn endgame of rook versus rook + knight) 3. ... Bc3 4.Rb8 Bxb4! 5.Rxb4 Rc6 6.Rh4 (6.Rb8 Rc4+ 7.Ka3 Ra4+! the rook is immune because of stalemate 8.Kb2 and black holds) 6. ... Rd6 and black holds as well


Free chess match database I'm working on a rating/ranking algorithm and I'm finally at a point where I can test some hypothesis but in order to do so I need real data. To be honest almost any board game could be used for this but I thought that chess is the board game with the highest possibility of having such a database.

I was thinking of posting it on other stackexchange pages but in the end I thought going to the root would be most efficient.

What the database should fulfill:

At least 50 players
At least 1000 matches
Downloadable (maybe not required if I can parse it from the website chronological)

Since I only play chess on rare occasions I'm not really too familiar with all the websites out there so I hope someone can help me.

Million Base 2.5 (available from a link here) and ICOfY Base are two free options that more than meet your given criteria, each providing millions of games in PGN format to draw from as you please. In particular, ICOfY Base includes well over 4 million games.


What are some physical chess simulators? My father likes to play chess but doesn't have any friends who would play with him. I suggested him playing it on tablet device but he doesn't like the touchscreen interface. He needs to touch the pieces.

Has anyone built a physical chess simulator (electricity powered, AI included) that will move the pieces on its own? I didn't find on googling.

EDIT. on further thinking I think it's hard to have such technology without using robots (one cannot just slide all the pieces - like Knights). May be if the board blinks lights below the piece it wants to move (with green light) and target location with another light (say red), then we can move opponents piece on the physical board.

Edit 2 Found this!: [Novag Obsidian] https://www.youtube.com/watch?v=7sAvribpPvA that kinda solves the problem. If you know better alternatives please post in answers.

Do you mean?

  https://www.youtube.com/watch?v=qS5EPbsmCXs

I don't know how you'd get his robot, but it won't be affordable.

Have you seen this page?

  https://chessprogramming.wikispaces.com/Robots


Running down the opponent's clock on purpose Running out of time is a loss. Two players are both very low on time and quite far from a checkmate. What if one player makes some 'pointless' defensive moves to keep his clock running so that the other player, still trying to win, runs out of time.

I am new and I am asking because I have had opponents moving their king back around while I was there trying to do something and had no time left.

Is there some sort of rule that prevents my opponent from making useless moves while I try to win and run out of time?

That's how it goes. Time management is an important part of tournament chess play.


The Pointing Rule and its relation on which side to attack? I was watching a video by NM Dan Heisman and in the video he mentions what is called the Pointing Rule.  He also makes mention that like many rules in chess, it should be taken lightly and not followed all the time.  He states that the Pointing Rule dictates where you should attack your opponent, so if your pawns are pointing towards the queen side, attack that side and if they are pointing towards the king side, attack that side, but what if they are pointing in two different directions? Besides the Pointing Rule, what other factors should one consider when deciding which side to attack?  I have always thought you should attack where they castled.  To illustrate the pointing rule, I will make 3 diagrams with some random moves

Both White and Black should attack the King side since both their pawn formations point towards each others king side:

[FEN ""]
1.e4 e5 2.Nf3 Nc6 3.d3 d6

Both White and Black should attack the Queen side since both their pawn formations point towards each others king side:

[FEN ""]
1.e4 e5 2.Nc3 Nc6 3.f3 f6

The pawns for both sides point in both directions, so where to attack now?:

[FEN ""]
1.e4 e5 2.Nc3 Nc6 3.d3 d6 4. f3 f6

The examples in your question are not great for this "pointing rule".  In general, this rule of thumb only holds when there is a locked pawn structure.  In each of the examples, both colors can play for a pawn break by pushing the d pawn.

Here's a better example:

[FEN ""]

1. e4 e6 2. d4 d5 3. e5 c5 4. c3

Already, the plans for both sides are clear: white must play on the kingside with an eventual f2-f4-f5 push, and black must attack the c and d pawns with moves like Nc6 and Qb6.   In general, the extra space can be utilized to maneuver the pieces to support the necessary pawn break or to attack a focal point.

Look at another example from the Bayonet Attack in the King's Indian Defense:

[FEN ""]
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. O-O Nc6 8. d5 Ne7 9. b4 Ne8 10. a4 f5

Once again, the center pawns show the correct plans for both sides - white defends on the kingside and attacks on the queenside while black goes all out for a kingside attack.  White has a huge lead in space - enough to be nearly "positionally winning", however black has sufficient play in the form of the attack and the opening is dynamically balanced and has been seen in top level play over the last few years when black is playing for a win.


What was Verdoni's first name? Did you know that Verdoni was known to be a chess champion in the 19th century, but what was his first name?

To expand BKFM's comment, this article says:

  Verdoni, dessen Vorname und Geburtsjahr unbekannt sind, soll
  italienischer Herkunft gewesen sein. Sein schachliches Wirken vollzog
  sich in Paris und später in London.

This translates loosely as " Verdoni, whose first name and date of birth are unknown, was of Italian stock. His chess career was in Paris and later London."


Is there a full tutorial for Queen vs Rook endgame? How do I convert the game into KQK easily, or simply mate? I've already learned the Philidor position.

Unfortunately, no "easy" fool-proof method is known. It can take 31 moves until the
 checkmate or capture the rook with best blay from both side in the worst possible
 initial position. Nevertheless, the queen can always win if the player with the rook
 has no perpetual check or a fast win of the queen or a stalemate trap.

In particular, you have to avoid stalemate traps. Human defence tends to lose faster
 because of the fear of putting the rook far away.

A difficult position is, for example W : Kd5, Qf7 S : Kd8, Rb6

where white has to find the counterintuitive move Qf4! which is not the only winning
 move but soon or later white must come to this idea to win.


How can I punish the "bad" knight on c3? I play the Caro–Kann Defence against 1.e4 as black, and for whatever reason it feels like I get the following line way too frequently:
[FEN ""]

1.e4 c6 2.d4 d5 3. exd5 cxd5 4. Nc3?!

This line is a "non-critical" line, so much so that I just got an opening book on the Caro-Kann and there are a whopping 0 lines that discuss how to play against this setup. It's very rarely played in the masters databases, but on lichess.org it's the 4th most common move in this position, and you can also reach the same position by playing 1.e4 c6 2.Nc3 d5 3.exd5?! cxd5 4.d4 which isn't too uncommon.
Similar to the c3 knight in the Richter–Veresov Attack or the "Jobava" London, mostly I just see people dismissing this knight, claiming off-hand that it's bad, that it "doesn't belong there". But for whatever reason, when I look at my results in the different lines in the Exchange Variation, this is my worst line! I'm probably running into problems with a small sample size, but I'm wondering if anyone has any general tips for how to make white feel this "bad knight".

I'm wondering if anyone has any general tips for how to make white
feel this "bad knight"

The fact that you manage to put "bad" and "bad knight" in scare quotes shows that there is some hope for you. White does not have a bad position. I suspect that this line isn't played much at master level because it isn't the best way to squeeze every last scintilla of advantage out of white's starting advantage of having the first move.
But there is no universe in which you can look at white's position and seriously think that white has a bad position which black must punish. If you think like that as black then you are on the way to losing.
Four moves into the game and white has already -

Staked a claim to the center with a pawn on d4 (black matches this with a pawn on d5)
Developed a piece to a good central square, the knight on c3 (black is behind but it is black's turn so can remedy this on the next move)
Has free development for both bishops (black has free development for only one bishop)

White is not worse. Black is not better. Has black completely equalized? It doesn't look like it.
So, your best approach is to accept that white's first move advantage may have decreased slightly but your job remains the same during the opening - try and equalize via good development. How you develop your pieces will depend to a certain extent on how white develops. Pay attention to all the things you normally do during the opening and aim to reach an even middlegame where you can try and outplay your opponent.
At all costs avoid trying to punish your opponent. This will only lead to bad moves and an early loss.


Is chess a good game for recovering addicts? In this interview to FIDE Master and psychologist Maria Rodrigo the interviewer asked her about chess and addictions:

XL. There are those who are not able to prioritize and get hooked.
M.R. Yes, because the dopamine rush during a game can be brutal. And that is something you have to learn to control. If you don't, you start a game, and then another, and another… And there is no one to stop. You lose hours of sleep… The problem of addiction is more typical in men than in women. Men are more hooked on video games and women on social networks.

I am a recovering addict. I passed through this clinic in Barcelona to recover from my addiction to alcohol and cannabis. They had a group where they used chess as therapy, so as a lover of the game I said to myself that chess couldn't be harmful for my therapy. But they banned me from chess, arguing I played obsessively. They said I could play once my two years treatment is finished. It was true that I played lots of online blitz, but I felt disgusted: why was I banned when they used chess as therapy for others?
Nowadays, I am in the ninth month of recovery. I left the clinic and I went to a psychologist. I don't play online blitz, but I play correspondence and I joined my club to play standard over the board games. My psychologist approve it but he is not specialist in addictions. At the clinic they wouldn't approve I am playing before two years of recovery.
I can read articles like this one on Chessbase where it is said they started a cognitive training through chess at a therapeutic community "recovering the cognitive functions (attention, memory, etc.) deteriorated by drug use, with the help of chess". But maybe this is focused on teaching how to play chess to people that didn't play lots of online chess while consuming drugs. And dopamine plays a role in addictions. At the clinic they said we were addicts to dopamine highs, so reading FIDE Master Rodrigo I would say it could still be harmful to my therapy and bring me closer to a relapse.
It is clear chess is good to treat other mental diseases like schizophrenia, and it looks good to teach recovering addicts how to play chess to recover the cognitive functions damaged by drug abuse (according to Chessbase article and my clinic), but is chess good for a recovering addict that played chess before his treatment started? Can it bring the patient closer to a relapse in drug use?

Stack Exchange has a site dedicated to medical sciences.
If you open that, you'll immediately see that on the right column there's a disclaimer that you won't find on any other Stack Exchange site. It's a bit long, so let me cut the most important parts:

Stack Exchange Inc., and its sites including Medical Sciences Stack Exchange, is not a medical practice or healthcare provider and does not provide medical advice.
[...]
Consult your own doctor for medical advice.
[...]
Medical Sciences Stack Exchange is for information exchange only, and is not a substitute for medical advice, individualized diagnosis or treatment by a healthcare provider.

This obviously covers the legal aspect, but it's more than that. Even if there were no lawyers and lawsuits in this world, that disclaimer would still have value. Because, well, it's true. In general you cannot trust users on any of these sites to really know what they are saying. Your health is too important to blindly trust some random stranger on the web, no matter how high their reputation is or how sincerely they are trying to help.
Besides, it seems to me that you've already got the answer from your clinic:

But they banned me from chess, arguing I played obsessively.

I'm sorry, but I'm afraid you'll have to accept it.
I hope I won't sound judgmental if I tell you that what you are really doing here is not looking for an answer (you've already got one; only, it's one you don't like), but rather for an excuse that will let you keep playing and ease your conscience.
Imagine someone posted an answer along the lines of

Don't worry, those doctors don't understand anything! Playing chess can't be a problem, just go ahead and play as much as you want!

I suppose you'd be very happy to read it. And yet, who would you rather trust: the doctors that visited you and know your case specifically, or someone who probably has no idea what they are talking about, and who certainly doesn't know you, your clinical history, anything about you at all?
So do the right thing, and do what your doctors say. Or in any case discuss with them what you should do.
My best wishes for your full recovery!


Is there some method to show attacks and defends and other statistics on board? I want to teach children basic rules of openings and show them some critical point in formation with some kind of visualization.

How can I show attack, defends, weak points or other statistics on board?

You could use Chessbase on a laptop to show games and positions. That would allow you to highlight critical squares and show possible moves with colourful arrows. Here is a description how to do this.


How to play king's indian attack aggressively? The King's Indian attack is my choice of opening. I choose this because more often I would prefer games where the actual clash between the sides is delayed (rather than outright in the opening). My friends have recommended me to prepare myself with more aggressive lines in the KIA. He specifically talked about pawn storming ideas (possibly with sacrificing a pawn) starting with h4. But, I guess this is not practical always.

Is there a way to play King's Indian attack aggressively against most systems adopted by black? (I don't mean same attacking plan irrespective of opponent's system). If yes, how?

I personally prefer double-edged games.

PS: There is a book on KID: King's Indian Warfare by Ilya Smirin. Is there a book of this sort on KIA?

I looked you up on FIDE's website, and as a roughly 1500-player, the KIA naturally fits your question "How to play king's indian attack aggressively?" If you play it correctly, it already IS an aggressive opening. You cannot get any more aggressive than an opening that basically says "I want to mate your king".

The reality is that at higher levels, it is mostly de-fanged, and considered only good for equality, which is why you do not see Carlsen, and other world champions, play it often (at best). At the top levels, it is played mostly as a surprise opening, typically, to avoid home preparation, or when a player just wants a playable game where the opponent is mostly on their own. Generally, black is considered to have adequate defensive systems that should render that attack harmless. However, black cannot underestimate white's kingside attacking chances, and even GMs can make mistakes in that opening, and lose to an attack.

You can play the KIA against the main black 1.e4 defenses: The Sicilian, French, and Caro-Kann. It becomes more difficult to get the type of game you want if black knows what you typically play, and plays and early g6, Bg7, and 0-0. It is just harder to go for mate against that setup.

As far as books go, there are dozens of books on the KIA. For your level, I would focus on books that explain the ideas rather than rely heavily on regurgitating a ton of theory. I have many books, but unfortunately, during a move, I lost most of my opening books, so I literally have no books on this opening, but if I were to recommend two book just based on a search, I would try these two: "King's Indian Attack: Move by Move" by GM Neil McDonald, and "Starting Out: King's Indian Attack" by GM John Emms. They seem to be more of the explaining type (you can look at the first few pages on Amazon).

A word of warning: If you have any real intentions of trying to get to 2200, you may find that you have to develop a new opening repertoire from scratch at some point, as this opening is will limit your chess development in the long run since you will be easy to prepare for.


Hitting the clock without moving In an official blitz game, what happens if a player hits a chess clock without making a move? I believe that making an illegal move in a blitz game is an automatic loss. But does this count as an illegal move because my opponent didn't really make a move?

You can only make an illegal move by making a move. Pressing the clock without moving is not making a move. So the arbiter can't use that rule to make a decision.

There is FIDE rule 6.13 (chapter 6 is about the clock): "If an irregularity occurs and/or the pieces have to be restored to a previous position, the arbiter shall use his best judgement to determine the times to be shown on the clocks. He shall also, if necessary, adjust the clock’s move counter."

So the arbiter can use his best judgement to reinstate the correct clock times. This is of course unfortunate (it's hard to stay concentrated for the players, especially the innocent player), but the arbiter can't just invent rules.

If this happens regularly (the player is doing this on purpose), there is always article 12.8: "Persistent refusal by a player to comply with the Laws of Chess shall be penalised by loss of the game. The arbiter shall decide the score of the opponent."


PGN-Extract output each game to a separate file with name like opponentA-opponentB.pgn How can I use PGN-Extract to split a multi-game pgn into separate files with just one game per file.  With the pgn being named for the opponents?  Like opponentA-opponentB.pgn

To a limited extent, you can do something like this already using the -Tp argument which selects games by a particular player. So:

pgn-extract -TpLeko --output Leko.pgn games.pgn

but there is not currently (2018.12.19) a way to have the file names generated automatically from the contents of the source file. Without a way to bound the number of players of interest this would require a lot of file opening and closing for a large input file. Some thought would also need to be given to how player names are mapped to file names.


How to I apply moves (bitboard) and continue searching? My current attempt is throwing a strange error! Explanation
I have a list of all possible current moves in a position. At each node, I want to then generate all possible moves and continue. The problem is that my code is modifying the list of moves in the node above. At least I think this is the case!
I am open to completely changing the way I handle moves, as I feel this isn't very efficient since I have a struct for every move.
Output
This is the current output.
PS D:\Users\kmont\Desktop\ChessEngine> dotnet run
Number of moves at depth 1 is 4. It is White's turn.
Number of moves at depth 2 is 4. It is Black's turn. Previous move was knight to a3
Unhandled exception. System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
    at System.Collections.Generic.List`1.Enumerator.MoveNextRare()
    at System.Collections.Generic.List`1.Enumerator.MoveNext()
    at Program.search(Int32 depth, Board board, String prevMove) in D:\Users\kmont\Desktop\ChessEngine\Main\main.cs:line 55
    at Program.search(Int32 depth, Board board, String prevMove) in D:\Users\kmont\Desktop\ChessEngine\Main\main.cs:line 60
    at Program.Main(String[] args) in D:\Users\kmont\Desktop\ChessEngine\Main\main.cs:line 33

Code
The Move Struct:
public struct Move{
    public Piece.Type pieceType;
    public UInt64 piece;
    public UInt64 moveTo;
    public int color;

    public bool quiet;
    public UInt64 capturedPiece;
    public int capturedColor;
}

Search function:
public static void search(int depth, Board board, string prevMove = "nothing"){

    // If at the end of the tree, return.

    depth++;
    if (depth == maxDepth) return;

    Console.Write("Number of moves at depth {0} is {1}. It is {2}'s turn.", depth, board.allMoves.Count, board.color == 0 ? "White" : "Black");
    if (prevMove != "nothing") Console.WriteLine(" Previous move was knight to " + prevMove);
    else Console.WriteLine("");

    // Uncomment below line for a list of all possible moves.
    //if (true) foreach (Board.Move move in board.allMoves) Console.WriteLine(String.Format("    {0} {1} on square {2} can move to {3}.", move.color == 0 ? "White" : "Black", move.pieceType.ToString(), help.square(move.piece), help.square(move.moveTo)));

    foreach (Board.Move move in board.allMoves){
        Board newBoard = board;
        newBoard.color = 1 - board.color;
        initialiseBoard(newBoard);
        newBoard = makeMove(newBoard, move);
        search(depth, newBoard, help.square(move.moveTo));
    }
}

Make move function:
public static Board makeMove(Board board, Board.Move move){

    string moveColor = move.color == 0 ? "White" : "Black";
    string boardColor = board.color == 0 ? "White" : "Black";
    string pmove = help.square(move.moveTo);
    //Console.WriteLine(String.Format("    Making {0} move {2}: It is {1}'s turn.", moveColor, boardColor, pmove));

    Board toReturn = board;
    // Remove piece from board
    if (toReturn.color == 0 & move.color == 0){
        if (move.pieceType == Piece.Type.Knight){
            toReturn.WhiteKnightsBitboard &= ~move.piece; // Get rid of piece on board
            toReturn.WhiteKnightsBitboard |= move.moveTo; // Add piece to board
        }
    }
    else if (toReturn.color == 1 & move.color == 1){
        if (move.pieceType == Piece.Type.Knight){
            toReturn.BlackKnightsBitboard &= ~move.piece;
            toReturn.BlackKnightsBitboard |= move.moveTo;
        }
    }

    Game.node++; // To count nodes
    return toReturn;

}

Initialise Board function:
static void initialiseBoard(Board board){
    BoardOperations.updatePieces(board); // Sets all pieces and finds empty squares
    board.generateAttackSquares(board);  // Finds white knight moves and puts them into board.allMoves
}

The issue may be here:
Board newBoard = board;

This creates a new variable, but it doesn't actually create a new Board. board and newBoard are pointing to the exact same Board object. So, when your code changes anything in newBoard, it also changes it in board, and when it changes, you get this error.
What you may want to do is make an actual copy of board, so when you change it, it doesn't change the original.


How many moves needed to reach this position? "Homebase" is where all the surviving pieces are apparently on their starting squares. Here is a very easy new example proof game: can you find the unique shortest game that leads to this position?
[Title "A.Buchanan 26-11-2020: shortest proof game?"]
[FEN "rnbqkbnr/ppppppp1/8/8/8/8/PPPP1P1P/RN2K1NR w - - 0 1"]

Yes c1 is empty!

I have no idea about this kind of problems, but my guess would be something like this.
[FEN ""]

1. g4 h5 2. Bg2 hxg4 3. Bf3 gxf3 4. Kf1 fxe2+ 5. Kg2 exd1=R 6. Kf3 Rxc1 7. Ke2 Re1+ 8. Kxe1

Is that unique? I have no idea.


Looking for tips on memorizing positions After watching a series of ChessBase India videos on YouTube, it is clear that GM's can easily remember 100s (possibly 1000's) of positions. Look at this one example by Vidit Gujrathi: https://www.youtube.com/watch?v=UebAM1CDxn8

My question: For amateurs, what are some good strategies to try to recognize a position and understand which opening it came from?

You really have a couple of questions here.

First, when it comes to memorization in chess, it has been shown that the more positions you have seen, the more likely you are to remember other positions. I remember once that GM  Susan Polgar was given some random chess positions, and she remembered the "normal" ones exceptionally well, however, when the positions were more random, she remembered at a rate that was roughly what anyone else remembered them.

There are books, unrelated to chess, that deal with learning to memorize better. I would love to see Master Simon Reinhard, World Memory Champion, write a book on memorizing specifically aimed at chess memorization.

Here are a couple more articles specifically on memorization that you might find interesting.

Memory Techniques: the Peg system (Part One)
Memory Techniques: the Peg system (Part Two)
Memory Techniques: the chess equation

Your second question, "what are some good strategies to try to recognize a position and understand which opening it came from?", is more about applying any memorization techniques to learning opening pawn structures, and the plans that are associated with them.

There are many books on this from the very basic, "Chess Opening Essentials: The Complete Series" by New In Chess to the classic "Pawn Structure Chess" by GM Andy Soltis to the more advanced, and outstanding, "Chess Structures: A Grandmaster Guide" by GM Mauricio Flores Rios.

These types of books teach you what you are aiming for in the opening, in general, and thus, when your opponent does not play "book" moves, you are not just lost with no idea what to do. You just have to read these types of books, and absorb some of the positions, and then you are back to the experiment with GM Polgar, even if not on the same level. You will begin to memorize, and recognize more.


Why is Kh8 the best move in this position for black? Why is, according to Stockfish (depth = 28), Kh8 the best move here for black?

This is a position from a game between Emanuel Lasker and Wilhelm Steinitz, 1896.

Nb6 seems to be the natural move in this position. At least to me (an intermediate player).

Yes, there is a check at Qb3 or Bc4. But what's the big deal? The b7 pawn is protected if Nb6 is played. Bc4 is also not an option then.

It's not a machine-like move. Steinitz played this, not in this move, but in the next move. Kh8 is not even among my [an intermediate player :-( ] candidate moves.

This is the first time I am posting in stack exchange. Please excuse the bad formatting of the question. I don't know how to add PGN here so that you guys can go through the game move by move.

If you don't play ...Kh8, then for every move you consider making, you're going to have to worry about what happens if White responds Qb3+ or Bc4+. If you're analyzing variations, you always have to take into account that White might play Qb3+ on the fourth move of the sequence or something. This means that

You're going to have to spend extra time on the clock every move checking those checks.
You might mess up and miss one of those times when one of the checks works, and get a disastrous result.
Even if you don't mess up, natural moves that you might want to play might fail due to one of the checks, and you'll have to play a less nice move instead.
When White looks for tactics, he has built-in "hooks" to try to build combinations around. If there's some other weakness in your position at some point, there's a decent chance some double-attack tactics will become possible, for example.

Of course, Stockfish only really cares about the last two, but even that's enough. If you can afford the tempo, it's a really good idea to just get the king out of the way and completely quash all four problems for the whole future of the game.


Bizarre pin rule: pinned pieces do not attack I found this guy who likes playing chess, but not enough to bother reading the rules; he only plays using a physical board with his sister (she doesn't know the rules either).

The made up rule was this:

  A pinned piece is not attacking the squares he can't reach the next
  move without exposing the king.

Which means, a lot of things can happen:

A king can move to an 'attacked' square if the piece is pinned.
By removing the pin, the piece now attacks the squares he wasn't (this can result in discovered checks if the king was in one of these squares).
You can remove a check by pinning the attacking piece.

If you think about it, it requires much more thinking process to play like this. I was at a disadvantage because it is really hard to see these new threats and tactics if you never played like this before.

My questions:

Does anyone know if this is some kind of known chess variant?
Should I tell them the correct rules even when I know they are not that serious about playing?
Are these rules more complex to understand than the official pin rules?

Well, it's a variant (since it's played by your friend and his sister, and probably at least some others), but not a well-known one.  I used to think this idea would be only logical until I realized that a King moving into a square attacked by a pinned piece could still be captured by the pinned piece, and even though the opposing King would then be exposed to attack, the first side would already have lost.  Note that though Black leaves himself in check with his move, he still wins because he theoretically captures the King first:

[FEN "8/8/5k2/4r3/8/2B5/8/5K2 w - - 0 1"]

1.Ke1 Rxe1 2.Bxf6

Compare with a position in which it's a mate in one for whichever side moves first.  Say White checkmates, then Black has lost even though he can checkmate in one move.  This is due to the same reason that Black won in the previous diagram.  Theoretically, White wins because he can capture the opposing King first:

[FEN "6k1/5ppp/6r1/8/8/1R6/PPP5/1K6 w - - 0 1"]

1.Rb8# Rg1# 2. Rxg8 Rxb1

To your second question, I see no reason why you should not let them know the real rules.  You are the best judge of whether he'd be open to learning them.  Don't be overbearing and certainly be willing to play his variant if he obviously doesn't care for the standard rules.  Games are for fun.

And to the extent that it requires consideration of more possibilities, it is more complex tactically.


Does threefold repetition take into account the side to move? To be more clear, here is a fragment of a game:

[FEN "4k3/R7/6r1/3KP3/8/8/8/8 w - - 0 1"]

1. Ra2 Rg5 2. Ra7 Rg6 3. Ra2 Rg5 4. Ra7 Rg6 5. Ra4 Rg5 6. Ra2

From the FIDE Laws of Chess:

  5.5.1 d.
  The game may be drawn if an identical position is about to appear or has appeared on the chessboard at least three times (see Article 9.2).

The position of the pieces occurred three times. However the board position only occurred twice. In the first two occurrences, it was white to move. In the final position, it is black's turn. Can I claim a draw by threefold repetition in this situation?

You quote an extract from the FIDE Laws of Chess which includes the simple instruction "see Article 9.2" yet you don't bother to "see Article 9.2" where your question is answered -

  9.2.1 The game is drawn, upon a correct claim by a player having the move, when the same position for at least the third time (not
  necessarily by a repetition of moves):
  9.2.1.1 is about to appear, if he first writes his move, which cannot be changed, on his scoresheet and declares to the arbiter his
  intention to make this move, or
  9.2.1.2 has just appeared, and the player claiming the draw has the move. Positions are considered the same if and only if the same player
  has the move, pieces of the same kind and colour occupy the same
  squares and the possible moves of all the pieces of both players are
  the same. Thus positions are not the same if:
  9.2.2.1 at the start of the sequence a pawn could have been captured en passant
  9.2.2.2 a king had castling rights with a rook that has not been moved, but forfeited these after moving. The castling rights are lost
  only after the king or rook is moved.

Note in particular "Positions are considered the same if and only if the same player has the move"


Storing chess position in 24 Bytes I want a fast way to search how many times a certain position has appeared in a database of hundreds of thousands of games. I researched the best way to store positions in a database but all of the solutions were quite large and were stored as strings.
I thought of a different way and I was wondering if this would work or if there are some corner cases I did not consider.
Remember, the point of this storage would be to quickly search if a position had ever been reached before and not used to reconstruct entire games.
The first table would be int id, and BINARY(8) pieceExist
Starting from the top left of the board and reading to the right a1 would be set in a 64 bit number if any piece exists in that square and a 0 otherwise.
I would search this table first and retrieve a list of ids where pieces were in the same position as the board I am looking at
The next table would be int id (foreign key from the first table) Binary(16) pieceSpecification
This table specifies what piece is in each position, for every square where a piece exists you create a 4 bit number which would specify color and type of piece, which would has only 12 unique combinations. You would not need to store any information on where this piece is placed on the board as that is specified in the 64 bit number in the other table.
You would then find all ids where the pieceSpecification number you constructed has an equivalent value in the table.
You could probably off the database do a joint on the two sets of ids to see how many times your position has appeared in the database.
I reckon this approach has many benefits. Space in the database is minimized and searches would hypothetically be able to be completed in a matter of milliseconds.
Let me know if there are any problems with this or perhaps a better approach I could use.

You can use the first 64 bits to encode which squares are occupied, and then encode what's in the occupied squares one by one, using four bits per square for up to 32 occupied squares.
The four bits allow sixteen possible piece types. There are only twelve types of pieces, but this lets us get in some additional necessary information. Here's an example encoding scheme.
0 - white pawn
1 - black pawn
2 - white knight
3 - black knight
4 - white bishop
5 - black bishop
6 - white rook that can't be castled with
7 - black rook that can't be castled with
8 - white rook that can be castled with
9 - black rook that can be castled with
A - white queen
B - black queen
C - white king if white has the move
D - black king if black has the move
E - the king that doesn't have the move
F - a pawn that has just advanced two squares
This should be enough to specify the position (piece locations, player to move, castling rights and en passant, but not fifty-move counter or move number).


Forced checkmate examples where engines fail Do you know example where recent chess engines (Houdini, Rybka, Komodo, ...) failed to find a forced checkmate.

I guess they must find mate in 1 or 2 all the time but maybe are they failing to be as creative as human some times.

Positing this answer in addition to the answers/comments on tablebases and endgames with ridiculously long forced mates.

White to move and win (I do not know the author of this study, unfortunately). The engines will tend to fail on this and similar problems.
As far as I tried, all recommend to move hxg8=Q. Some show 0.00 and are soon thereafter putting black in a stalemate; some show slight advantage for white and are trying to play the game out by letting black to activate his pieces. Further explanation (and hint to the solution) given in the spoiler block below the diagram.

6r1/p1p1p1pP/P1PpP1P1/8/2P1B3/2K3pp/3P2rq/R5bk w - - 0 1

Explanation spoiler:

   The forced mate is not found because the engines use pruning heuristic. It removes certain branches from search tree, after deeming them as irrelevant to the search result (see: http://chessprogramming.wikispaces.com/Pruning). In case of this puzzle, the solution consists of many subsequent sacrifices and its branch tends to be discarded when searching. Note: Possibly, with tweaked parameters and mate-search heuristic when exact number of moves required is provided, they could find the solution, but I have not tried that.

Solution spoiler:

   Depending on black's move choices, a few solutions exist (the idea is always the same, though and up until move 12 the line is always the same, too). Here's an example: 1. hxg8=N d5 2. Bf3 d4+ 3. Kb4 d3 4. Nh6 gxh6 5. g7 h5 6. g8=N h4 7. Nf6 exf6 8. e7 f5 9. e8=N f4 10. Nd6 cxd6 11. c7 d5 12. c8=N dxc4 13. Nb6 c3 14. dxc3 d2 15. Kb3 d1=Q 16. Rxd1 axb6 17. a7 b5 18. a8=Q b4 19. Be2 bxc3 20. Bf1 c2 21. Rc1 f3 22. Qxf3 Bf2 23. Bxg2+#


Repertoire book on the Ruy Lopez exchange variation? [FEN ""]
1.e4 e5 2. Nf3 Nc6 3. Bb5 a6 4.Bxc6

Is there a good opening repertoire book for White advocating the Ruy Lopez exchange variation?

Larry Kaufman's The Chess Advantage in Black and White is a well-regarded (though old, by opening book standards) repertoire book that uses the Ruy Lopez exchange.


Maximum number of knights populating a chess board so that no knights are attacking one another The 8 queen's puzzle is a well-known puzzle involving placing 8 queens on a chessboard so that no queen attacks another queen. It is more or less obvious that 8 is the maximum number of queens that can populate a chessboard so that no queens are attacking each other.
But what if we use knights instead? How many knights can we maximally place on a chessboard while still satisfying the stipulation of no piece attacking another piece? So far the maximum I've achieved is 24, attained by placing a cluster of 4 knights in the center, and on every square on the edge of the board except for c1, a3, a6, c8, f8, h6, h3, and f1. I cannot see how this number is improved, although I haven't proven that 24 is the theoretical maximum yet.
Additionally, what happens if we use bishops? The maximum I've achieved is 14 at the moment, placing as many as possible along the edges. But this one I haven't really tried to optimize very much.

14 non-attacking bishops
We may consider the white-square bishops and the black-square bishops separately.
At most 7 bishops can be placed on white squares, namely, at most one bishop on each of the 7 white diagonals parallel to the h1-a8 diagonal. In fact, we can put bishops on the 7 white squares b1, d1, f1, h1, c8, e8, g8.
The solution for black-square bishops is just the mirror image of the solution for white-square bishops. At most one bishop can be placed on each of the 7 black diagonals parallel to the a1-h8 diagonal, and this can be achieved with bishops on a1, c1, e1, g1, b8, d8, f8.
32 non-attacking knights
We can put 32 knights on the board by putting knights on all the white squares or on all the black squares.
One way to see the we can't have more than 32 knights is to consider a knight's tour. If we number the squares from 1 to 64 in the order they are visited by the touring knight, then it's clear that our non-attacking knights can occupy at most one of the two squares 1 & 2, at most one of squares 3 & 4, at most one of squares 5 & 6, and so on.
But a knight's tour is somewhat difficult, and not really needed for this problem. All we really need is to divide the 64 squares of the chessboard into 32 pairs, each pair being separated by a knight's move. Since the 8 x 8 board can be cut up inti eight 2 x 4 boards, it will be enough to observe that the 2 x 4 board admits such a pairing (and therefore can hold at most 4 non-attacking knights), namely a1 & c2, a2 & c1, b1 & d2, b2 & d1.
Non-attacking knights on variant chessboards
It can be shown that, provided m,n > 2, the maximum possible number of knights on an m x n chessboard is ceiling(mn/2), that is, it's mn/2 if mn is even, (mn+1)/2 if mn is odd. This number can obviously be attained by putting all the knights on squares of one color. Proving that it's optimal is more work.
Let's say that an m x n chessboard has a "good pairing" if the set of squares can be partitioned into pairs (with one square left over if mn is odd), each pair being connected by a knight move. The existence of a good pairing follows from the existence of a knight's tour, but good pairings are easier to find than knight's tours. It will suffice to show that a good pairing exists whenever m,n > 2. In fact, it will suffice to show that a good pairing exists for 2 x 4, 3 x 3, 3 x 4, 3 x 5, 3 x 6, 5 x 5, and 5 x 6 chessboards, since every m x n chessboard with min(m,n) > 2 can be partitioned into rectangular pieces of those seven sizes, without using more than one piece with an odd number of squares. Constructing good pairings for those seven small boards is left to the reader. (The 3 x 4, 5 x 5, and 5 x 6 boards allow knight's tours.)


How can I make a chess exhibition exciting for 'laypeople'? I've been asked recently to try to put on a few chess exhibitions for some local kids and their parents in a mostly urban setting, and one thing that I'm keenly aware of is the basic 'uncoolness' that surrounds the game for some people.  I'm trying to fight that tooth and nail, and doing that means figuring out how to make the game Fun with a capital F.

One idea revolves around 'slam chess', which one of my acquaintances from DC introduced me to.  Basically it involves allowing extravagant moves (such as tossing your queen up in the air and catching it before moving her) and allowing mild smack talk if someone falls for a trap or something.  Doing some research, it turns out Maurice Ashley learned chess this way.  I've never been introduced to this before so I have no idea how people will react to it.

Another idea is to get deconstructionist and to not worry about the overall game as much as putting up a bunch of tactical problems that people can engage and solve, with people giving hints if need be, with the ultimate goal having people solve 3-5 tactical problems to frame chess as a bunch of little victories instead of one longer game.

The big goal is to make the game exciting and get the human element involved in it; the two big pieces of feedback I heard when asking around were after the fashion 'nobody plays chess' or 'it's too much work to learn'.  The solution as I see it is to just make the game fun, then people play and it's not work to mess with it (it's fun).  I'm decently familiar with programming, video editing, etc so if anyone has a particular idea for websites or media production to help a presentation I'm all ears as well.

PS: I saw this question, but it more related to talking to individual people than putting on a show for a group.

I've been to a lot of events that have featured the live-action chess game. It's usually a big hit with people not normally into chess. Make a giant chess board with paper or tape or whatever and bring costumes along for people to act as the pieces. You'll want to run quick games that way so the people don't get bored. And be prepared for the kids to get antsy and run off. Having some backup players on the wings to take over can be helpful.

Try to work up a crowd with a couple "main events", and steer people around to the shorter things like your tactical idea on the side-lines. More often than not, a big crowd in one part will create interest for others, even if they wouldn't be interested normally.


Why is Fritz 16 Grandmaster Playing Weak Endgames? I am trying to use Fritz 16 to practice endgames. Unfortunately, Grandmaster (Fritz) is playing very poorly. For example, in the diagrammed position, if I play Black, Fritz gives me a quick threefold repetition after 1 Ke4 Nc6 2 Kf5 Na7. But when I play White, Fritz resigns after 1 Ke4 Nc6 2 Kd5 Na5 3 Ke5 Kg7 4 Bd5 Kg6 5 Kd4 Kf6 6 Kc3 Kf5 7 Bh1 Ke5 8 Bg2.

[title "White to move"]
[fen "7k/8/8/2P1n3/8/4KB2/8/8 w - - 0 1"]

1. Ke4 Nc6 2. Kd5 (2. Kf5 Na7) Na5 3. Ke5 Kg7 4. Bd5 Kg6 5. Kd4 Kf6 6. Kc3 Kf5 7. Bh1 Ke5 8. Bg2

Why is Grandmaster (Fritz) playing this ending so poorly? Do I need to change the settings? It doesn't make sense that the engine resigns with Black, but plays a draw by repetition with White.

Any ideas? Are there settings I can change? I have triple checked that I have set the engine to Grandmaster level.

Fritz's 2.Kf5 is a mistake because 2.Kd5 is the only winning move according to the tablebase. Maybe Fritz suffered from the horizon effect (couldn't see far enough ahead) which turned the win into a draw. After that, a draw by repetition doesn't seem unreasonable.

Playing black, Fritz resigns but that's after seven moves, so the "horizon" is now closer, presumably close enough for Fritz to tell it lost (will lose the knight within a couple of moves with no way to stop the pawn).

I don't have Fritz, but from what I can tell "grandmaster" is one of its handicap levels (the strongest, but I'm guessing not as strong as running the engine at full strength). Handicapping an engine is not an exact science so maybe it does play this endgame in a way that's weaker than an actual grandmaster. See if there is any setting to play against the full strength engine. Also I think there is a way of getting Fritz to use a tablebase.


Can I move a piece protecting the king if it keeps protecting on its new location? Situation: there's a piece between the king and an opponent’s piece. If this piece were not there, it would be a check.

If I were to try and move the protecting piece somewhere and leave the king exposed, that move would be not allowed.

Could I move this protecting piece, even though when it's lifted the king is in check, but when the piece lands, the king is protected again?

Yes, that's legal.  For example:

[FEN "6k1/6r1/8/8/8/6R1/8/6K1 w - - 0 1"]
[SetUp "1"]
[CurrentPosition "6k1/6r1/8/8/8/8/6R1/6K1 b - - 1 1"]

1.Rg2

The rook can move along the g-file.  This is known as a "partial pin" - the rook is somewhat limited in its movement (and can't go to a3, for example) but it can still move if it still protects the king.


Is there a list of ALL potential mates/traps under 10 moves or so? Wiki has a couple of pages on opening traps, but I get the sense there must be more, and these are just representative samples:

List of chess traps
Checkmates in the opening

PS. The "10 move" limit is really just for practical reasons - I know that the opening can be longer, but I am just looking to make sure I don't fall for any famous trap early on in the game....

I would suggest investigating Bill Wall's Chess Page, specifically:

700 Opening Traps
Miniatures that relate to your favourite openings, e.g. 500 Caro-Kann Miniatures
The PGN files related to you favourite opening


Preparing for an OTB tournament: I must do well! To give a picture of my level: I started playing chess fairly recently (8 months ago). I knew the rules before, but haven't played since childhood. I developed a huge passion for it and studied very, very hard and with a lot of commitment. I have 2080 Lichess elo on Classical time formats, which is decent but still not fantastic.

In my college, I was invited this year to represent my faculty on the University Chess Olympiads, and I became part of a team of very experienced players, all of which play tournaments since a very young age (I'm 21 and I have only played two very casual tournaments!).

This Friday we will face another university on a friendly competition, and this will be my first tournament as a member of my University team. Of course I want to do well, since I want to make a good impression on my team members, prove them that inviting me to the team was not a mistake, but I have too little experience on OTB tournaments.

My first tournament I did well, winning 4 and losing 6 games (I was 1700 Lichess elo then). My second and last tournament I did HORRIBLE, losing 6 out of 6 games (!) and falling fully under the pressure and tension of the tournament. I was 1900 Lichess elo then. My nervousness was such that I lost won positions, or hang pieces, things that I do not do (except rare exceptions)  when I play on Lichess. That was the first realization I had that OTB tournaments, with all their pressure, and playing comfortably from my couch, where two completely different worlds.

With all this said in order for you to understand my background and chess experience I ask: how can I prepare for an OTB tournament? I really want to do decently this Friday, and I need to keep my head cool and control my nerves. Advises for this tournament beginner?

First, from a pure chess standpoint, you are probably as close to prepared as you will be since there is only so much you can learn between now and Friday.

The most important things will be to get a good night's sleep, and the cardinal rule in a team tournament is "don't lose". I know that sounds funny, since it seem obvious, but if you have a four-board team, and you lose, then the remaining three players have to go 2.5/3 to win the match. What that means is that, in practice, you cannot play too wildly since wild play can put the team in a very bad position. Stay solid, and if you can win, great; but be satisfied with a draw if you really do not have anything more.

As far as the nerves are concerned, they are a problem; but you will find that the more you play, the more you will get used to tournament play, and the nerves will subside.

Lastly, at the board during the game except for obvious recaptures, and assuming you have the time, just BRIEFLY consider every reply your opponent has before you make your move. In other words, I am going to play Ng5, but for a second, I just scan every move my opponent can make. I am not analyzing, but subconsciously, if I left something hanging, I often notice it. This will hopefully cut down on the one-, or two-move, blunders


Can the book 'Grand master Preparation: Calulation' by Aagard be useful for a Class B chess players? I heard in most chess forums this book is for 2400+. Can this book also be useful for Class B players? I'm looking for a book to improve my calculation and planning. If so, in what ways? What would be the best way to self-study this book as a Class B?

I'm rated around 2150 Elo and I used the book two years ago, to solve exercises on the way to work. I could solve approximately 50%, which felt somewhat disheartening, though objectively, I guess, it's pretty ok for my level. I definitely profited from the training.

I wouldn't recommend the book for players significantly weaker than me. Mostly because it's demotivating if you are always struggling to even think in the right direction. I have found that the final instalment of the Yusupov series fits my own level better (i.e. tough but solvable).

But if you can keep your motivation up, even without much positive feedback, of course you can profit from thinking deeply about just about any position.


How to get opening analysis published and in ECO? My friend and I have done substantial research on a number of various lines over the years, and now that we are not really active anymore we were hoping to publish some of the gems.  Most of the analysis is in uncommon openings (Veresov, Bird's, Budapest) so we are pretty confident that it isn't already known.  Our goal was to see some of our lines in MCO or to have a variation make its way into ECO; we think it would be really cool to be using Fritz to look at a game and have it give the variation name as one that we analyzed.  How would we go about doing this?

Just a few ideas for you to try:

Have you checked the latest Mega and Corr databases to see if your lines/variations are in there?
If have access to a few powerful engines (Fritz, Shredder, Houdini and many others) run some analyses on them to see how they fare in terms of evaluating your lines.
You can make these engines play against these lines, and have your own "run-offs"
Show these lines to some strong players (IMs and above) and see if you can interest them in trying it out, or at least in getting their opinions. (It would be tricky to find players who have these openings in their repertoire if these are uncommon openings.)
I've personally found the Chessbase folks to be very approachable. (I am talking about quite a few years ago.) You can write to Frederic Friedel and ask to be put in contact with their resident opening experts. If the lines are good, they will figure out ways to add them to their opening books. (But you'll have to do the other steps first before approaching them. I suspect that they get contacted by many.)

Hope that helps.


Free offline demonstration software with arrows, sidelines and engine I'm looking for a software where I can demonstrate games in a lecture. The software shall have these features:

usable without internet connection on a Windows 10 PC
free
input and save a game as pgn easily
import pgn possible
possibility to easily draw arrows and mark squares
add variations by moving pieces
an engine with multi-pv showing at least the best four lines
bonus: engine can be chosen by me

I've tried these: Arena (no arrows), LucasChess (no variations), Scid vs PC (no arrows), Tarrasch (no arrows), Chesspad (no arrows), Lichess studies (not offline, no choosable engine), Chessity (not offline)
UPDATE: David Miedema's answer tells me that there is a comment window in Scid vs PC, that I can draw arrows and I can even mark squares with any of a lot of signs and colors. Marking squares on the main board with ScidvsPC is a bit clumsy - you have to mark them on the comment board first and then press a button to transfer to the main board.
Also, I found out that you can add marks and arrows and one engine in Chesspad.
UPDATE 2: In  between I found out that ChessX would also suit my requirements quite well. So there are ChessX, ScidVsPC, Chessbase Reader and Chesspad which would seem to be ok.
UPDATE 3: I added the two requirements: to input and save games. I took those to be a given.

Did you already give Scid a really good look?
Drawing Arrows
Arrows can be drawn in two ways. In the Main Board, hold Control and click on the start square and then end square. Or in the Comment Editor arrows can be drawn (and erased) by dragging between two squares.
Of course there is Chessbase in many sorts and sizes. You're probably able to find an old version for free if you search well.
Hope this brings you a bit closer.


Any website that shows which opening a certain player struggles against? Just thought it would be an interesting statistic to know which openings players like Carlsen and Fischer lost most against? Any suggestions?

Opening tree happens to be the website you are looking for, in it you use a database of games or someone's Lichess or chess.com username to get detail about their games. It shows frequency, last played, best win, worst loss, win-loss stats and performance. It also have have fatabases of famous players in it. Checking Anand's games as black, after playing 1.e4 2.c5 3.Nf3 his worst performance is in Sicilian Defense: French Variation (elo performance 2644) with score 107/173 and worsst loss was Ljubojevic - Anand 1998.

Overall, its a nice free website.


Can anyone explain the motives of this chess engine? I just played a game against a fairly low-level chess engine, and it made some really weird moves that i cannot see the logic behind. The game goes as follows:

[fen ""]
1. a4 d5 2. d4 Qd6 3. c3 Qg6 4. Bf4 Qxb1 5. Qxb1 Kd8 6. e3 Bd7 7. Bb5 Bxb5     8.
axb5 e6 9. Ne2 Be7 10. g3 Nd7 11. O-O g5 12. Be5 f6 13. Bxf6 Ndxf6 14. Qd3
Kc8 15. c4 Bb4 16. cxd5 Nxd5 17. Qc2 Nge7 18. e4 Nb6 19. Rfc1 c5 20. dxc5 Nd7
21. b6 Nxc5 22. bxa7 Re8 23. Qc4 Nc6 24. Nd4 Be1 25. Qxc5 Bd2 26. Rc2 Rxa7
27. Rxa7 Be1 28. Nxc6 Bxf2+ 29. Kxf2 Kc7 30. b4 Rf8+ 31. Ke3 Rf3+ 32. Kxf3
g4+ 33. Kxg4 h5+ 34. Qxh5 Kd7 35. e5 Kc8 36. Na5+ Kb8 37. Rxb7+ Ka8 38. Rc8#

The first weird move is 4. Bf4 Qxb1 which exchanges the queen for a knight.

The second illogical move is 26. Rc2 Rxa7, where black sacrifices their rook for a pawn, while already down a queen.

With 28. Nxc6 Bxf2+, black decides not to retake the knight and instead sacrifices a bishop to take a pawn and deliver a meaningless check.

Ke3 Rf3+ gives away black's rook, leaving the computer with no major pieces against both my rooks and a queen. The computer then proceeds to check me twice with pawns, both of which i take.
e5 Kc8 Is the most stupid move, leaving black open to a forced checkmate.

Considering that this computer is set to 'hard' difficulty, i am very dissapointed. Does anyone have any explanation for what might have caused it to make these pathetic moves? I would like to think that it is not designed to let me win, however by the looks of things it is.

The engine is only looking ahead one move. Most of these blunders are giving check, but are poorly constructed. It seems that the engine is programmed to think that giving check is always good, but does not check to see if its pieces are defended.


Python-chess : Are the move scores enough to rank moves from the most to least likely moves played by an engine? My goal is to make a script to finding the most and least likely move an engine will play, and then make a list it. I tried using the scores to make such a list, with the best score equalling the most likely move,  but every time I got d ifferent scores for the same position.

After compering high-scoring moves with engine moves with the code engine.play(board, chess.engine.Limit(time=0.100)), I noticed that the engine moves are totally different from the move that have the highest score on my outputs.

When I use the same version from my engine, but onvother sites that have the engine installed, I found that it chooses a different move from what my engine script chooses. I know that the engine is  not just a bot who is repeating moves every time, but what's the best way make it as such?

Here is my code if you want to have a look:

import asyncio
import chess
#import chess.uci
import chess.engine
import chess.pgn
import io
from chess.engine import Cp, Mate, MateGiven
#Let's try our code with the starting position of chess:

fen = 'rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1'
board = chess.Board(fen)

#Now make sure you give the correct location for your stockfish engine file
#...in the line that follows: e.g., /home/.../stockfish_6_x64

engine = chess.engine.SimpleEngine.popen_uci('/home/shar/Desktop/cheat detect python/stockfish-10-linux/Linux/stockfish_10_x64')

if board.turn: print( 'White to move');
else: print( 'black to move');
counter = 0
while counter < 1:
  # do processing
  counter = counter + 1

  result = engine.play(board, chess.engine.Limit(time=0.100))
  print('the engine move',result.move)

#getting legal moves scores part
for el in board.legal_moves:

    pgn = io.StringIO(board.san(el))

    thnwpgntofen = chess.pgn.read_game(pgn);
    nwinfo = engine.analyse(thnwpgntofen.board(),chess.engine.Limit(time=0.100));

    print(board.san(el),nwinfo.get("score"), nwinfo.get("depth"))

    print("-------------------------");

The volatility of the score here is caused by the time limit you have set. With time=0.100 you're restricting the engine to 100 milliseconds. With such a small time limit, there are a lot of small factors that can dramatically change the results. You can try increasing the time limit, or instead of using a time limit you can try a depth limit instead. This will make the engine search to a specific depth, rather than searching for a set amount of time. A depth limit will probably make your results more robust.

An example of depth limit would be:

chess.engine.Limit(depth=20)


Where to start with a child learning chess? From here:

What is the best age to learn chess?

it seems that consensus is that that kids can start learning chess at almost any age. From around 5 years old they are big enough to learn the names of the pieces and the rules for how each piece moves.

Here:

https://chess.stackexchange.com/a/6225

it is suggested to not push kids to learn chess, but to lead by example.

Here

Where can I start to learn?

there are tips for how adults can learn chess.

My question is: Assuming you have an interested child age 5 - 10, how do you practically suggest teaching chess? Does it make most sense to just start playing with setting up all the pieces, or are there smaller "games" that one can/should start with?

Does it make most sense to just start playing with setting up all the
  pieces, or are there smaller "games" that one can/should start with?

It doesn't really matter the age of the person learning to play, there is no point in starting with a full set. There is just far too much to take in and make sense of. The first thing to do is to teach them how to win!

So, first teach them how king, queen and rook move and then teach the basic mates -

KRR v K
KR v K
KQ v K

And I would do it in that order because it is the easiest and it is the way to introduce concepts like checkmate, king not allowed to move into check, two rooks working together, opposition, king and one rook working together, stalemate (to be avoided with KQ v K).

Next I would go on to KP v K, when you can win, when it is a draw and how to win.

Then I would go on to a game which many people start with (but there is no checkmate, so less fun IMHO) and that is 8 pawns v 8 pawns. Winner is the first to get a pawn to the other side or to "stalemate" the opponent - i.e. the opponent is the first to run out of moves.

After that I would reintroduce the kings and major pieces before finally going on to the full game.

You can see I'm working backwards here because that way the learner first learns where they should be aiming to get to and what to when they get there in stages starting from the destination.


Is it possible to download a big txt file containing many openings? I am creating a small chess engine for a CS class, nothing serious, i need to read the openings from a txt file or any format, i can go to websites like chessgames.com and download individual games, but i was hoping to download big files containing many openings and so much data, especially on the dragon variation, but any data will do. So is there a place where i can get my hands on that kind of data?

Thanks for all the guys who answered, I upvoted all of them and accepted the one I think is the best, so grateful for all of you guys, i just want to add a site that i found today by mistake, here

What you're looking for is a PGN file that contains several games. You can parse the game data and enter in the opening moves. A great resource is PGN Mentor where you can browse openings and download the appropriate PGNs.


Analysis of a position of a low rated player in order to improve I am a beginner in chess, and I am trying to learn how to play well. I am rated 800 in Chess.com, so I have a really low rating, and I am trying to improve it. I was playing a game and I have been in a position which I considered a good position in my opinion, but since it is the point of view of a beginner I would like to have a comparison with someone who is better than me at playing since the perception of what is a good position changes depending on the player.

I was almost at the beginning of the game and this was my position:

[fen "rn2kb1r/ppp2ppp/5n2/7q/4NPb1/3P1N2/PPP1B2P/R1BQK2R w - - 0 1"]

I had the white pieces and in this case is black turn to move. It was still the beginning so I am not sure it is possible to evaluate if the position is good or not at this early stage of the game.

Is it a good position? And which in your opinion would be the best move in this case?

I was thinking about moving the pawn in f4 to f5 in order to try to move the bishop to g5, which seems to me another good position.

What do you think? Thanks.

The first thing that comes to mind is that your king-side has been weakened quite a bit, but thankfully, it is your move. If it were black to move, you would be all but lost after 1...Nxe4 2. dxe4 Nc6, and Rd8 next since your queen would be forced away from your king, and it would likely perish to an attack.

 [FEN "rn2kb1r/ppp2ppp/5n2/7q/4NPb1/3P1N2/PPP1B2P/R1BQK2R b KQkq - 0 1"]

 1...Nxe4 2. dxe4 Nc6 3. null Rd8

In this position, even with you having the first move, I would still say that the position is more difficult for you. If you let it think for a moment, Stockfish rates it as slightly better for you, but if you do not play the EXACT best moves, it is easy to end up with black better. That is generally a sign that your position is not so great in practice since we are not computers.

Especially in the opening, you should post the moves that led up to this because I would say that you have made mistakes, and it is probably more important to correct those than worry about a position that is already tricky to play.

In this position, you have a few moves that do not lose immediately: Ng3, Be3, and Nf6+. The computer likes Ng3 the best and I will give that as the primary variation. The computer is not 100% sure about this variation, and often changes its evaluation on what is the best move for both sides as you go along, but you can see that many of the moves are not human. In cases like that, you are likely to play moves that are worse because you want to play positions that are easier to find good moves for you, and that make it difficult for your opponent to find them. Tal made a living off this principle.

 [FEN "rn2kb1r/ppp2ppp/5n2/7q/4NPb1/3P1N2/PPP1B2P/R1BQK2R w KQkq - 0 1"]

 1. Ng3 Qa5+ (1... Qg6 $4 2. f5 Bxf5 3. Nh4) (1... Qh6 2. f5 Qh3 3. Bf1 Bxf3 4. Qxf3 Qh4 5. Qxb7 $18) 2. Bd2 Qb6 3. Ng5 Bd7 4. Bh5 Nxh5 5. Qxh5 g6 6. Qe2+ Be7 7. Bc3 O-O 8. Qe5 f6 9. Qd5+ Kh8 10. O-O-O {And finally, it is clear that white is much better}


Is a forced draw by 50 moves possible with Bishop and Knight endgame? Except for the variations where there is a capture or fork possible for the defending side, is a position possible where this kind of endgame will last more than 50 moves? Is somewhere a calculation in moves done what is the worst possible situation?

It takes at most 33 moves to win this endgame from any position (excluding positions where bishop or knight can be captured). See https://en.wikipedia.org/wiki/Bishop_and_knight_checkmate and references there.

So, no, a forced draw is not possible in this endgame. However if the defending side is playing perfectly (e.g. an engine with tablebase), it could be very hard to win this for a human within 50 moves if you start from one of those 33-moves-to-mate positions.


What is the definition of an "outpost"? The Wikipedia definition of an "outpost" is this: “A position on the chess board where a knight is defended by a pawn from its same side.” Does it have to be a knight?

There is no "official" definition because there's no ISO standard for chess terminology, so the term means whatever the author wants it to mean, but I'd say the essence of it is that it is a "safe" and "advanced" square for a piece, where "advanced" typically means at least the 5th rank. As an analogy consider common non-chess definitions of outpost such as "an outlying or frontier settlement" or "a military base established in another country".

"A position on the chess board where a knight is defended by a pawn from its same side" is not only too restrictive by being limited to knights, but at the same time is too unrestricted because it would include something like a white knight on f3, which while protected, is hardly at an out-post; it's more of a "home base".

As for the "safe" part, it's a bit relative, but generally it means that it is not easy for the opponent to chase away or trade the piece. This may mean that the piece can't be chased away by pawns, because there are no pawns on the adjacent files or they are too far advanced, or because the pawn move to chase away the piece would come at a cost. Alternatively the opponent could trade it for a piece, but sometimes it's a bad tradeoff because the player who had the outpost might get some compensation such as a protected passed pawn. Or sometimes there is no way to trade it without sacrificing material, for example in a knight vs bishop scenario where the bishop is on the wrong color squares, so the only way to capture the knight is with a rook.

Finally, while not all outposts are for knights, perhaps most are; the reason for the emphasis on knights is due to knights being short-range pieces. Rooks and bishops can often be active from their home territory when on a good file or diagonal, but knights need to move closer to the action.


How popular is chess? There's a survey on chess.com, Do your friends play chess?, and the results aren't very encouraging. Personally, very few of my friends play chess.

Then I read this question: What's the most prestigious chess competition, broadcasted on TV? Chess was once broadcast on TV; is it getting less popular?

How many people actually attend the tournaments and watch them? I watch bowling, snooker, even darts on sky sport. Eurosport broadcasts sports like Biathlon; could chess be less popular than that? Really?

Is FIDE trying to make it more popular?

Chess isn't popular because all major tournaments make it lack emotion.  For some reason, all major tournaments are those of classic chess, that is, with high quality games that last 5 hours or more.  The outcome of these high quality games at the highest play level is most typically a draw.  This is totally broken and does not have a chance to make it to the mainstream public.

Now look at soccer, which has a bit of popularity in Europe and South America.  At the higher level there are few goals scored but games are more often than not full of emotion.  Just like chess, a small mistake (even a referee mistake) can determine the result of a game.  Just like chess, it is a game of mistakes, but there is a major difference: things happen fast, sometimes faster than the eye can tell. The center back does not let the forward to think as much time as he wishes so that he can make the shoot of the century. Instead, he tackles him.  The difference of level among a division and the division below is the time they have left to make a decision once they have the ball.  The higher the division, the shorter the time to think.

To answer your question, FIDE does not try to make chess more popular because it is promoting the classic games, which are of no interest and of a lot less quality than two machines playing against each other with a regular computer.  FIDE has been losing time trying to make chess an Olympic sport so that it can get funds by governments that are willing to increase their vanity each 4 years by getting Olympic medals.

If FIDE had any interest in making it more popular, the major tournaments where all money and fame are need to be of fast games, from 5 to 10 minutes by player, with lower quality but a lot more fun, and leave the perfect games for the machines.


How do I play 30 second games on chess.com? My current chess rating is approximately 1400 in 1 minute, 3 minute, and 5 minute games. I have seen some of the other players playing 30 seconds games whose rating is around 1200 but I cannot find an option to play 30 second games. How do I play 30 second games on chess.com?

Go into Live Chess.
Click on the left button right above the "Play" button. It should currently display some time control.
Click on the "More" button.
Click on the "30 sec" button. For custom time controls, you can instead click on the "Custom" button and enter what you want.


Did Hans Berliner win the world ICCF championship using computer help? Way back when, Hans Berliner worked for IBM.  I met him at an IBM data center one time, but he worked in the Federal division and just used the center for a demo. I had known him from the Washington Chess Divan earlier.
I know he had done a computer program to help with chess. It was the first as far as I can tell. This was in the days when the s/360 was ruling the market, and there were no PCs, and pdp8s and the like were not up to the job although they did cause IBM a lot of grief by their cheap price and what they could do for small special-purpose jobs.
The question I always had was did Hans use the IBM computers to assist his game when he won the ICCF world championship? I know that Hans was very good as a player,  but was he so good that he could have won the ICCF world championship without the computer's help? It is certainly possible, but having a really good computer analysis on some tough positions had to be helpful.

Short of asking a deceased man, I would say that the answer is "no way".

He won the 5th World Correspondence Chess Championship in 1965. Computer chess, if it existed at all, was not strong at all. Even with mainframe-type hardware back then, it paled on comparison to the first Chess Challengers of the early 1980's, and they were only rated about 1200 then.

My first chess computer in 1985, and it was the strongest and most expensive on the marker at the time, was only about 1600. There is no way that you could win against correspondence Grandmasters with that type of help.

I would say, fairly confidently, that is was all his work.


How to calculate initial Elo rating? I completed my first FIDE rated tournament with 0.5/3 points against Elo rated players. This weekend I'm going to another tournament, where I'll probably meet other 2 Elo rated opponents, completing the necessary condition for the first official Elo rating calculation.
Using the FIDE simulator (https://ratings.fide.com/calculator_rp.phtml) it seems that even if I lose I'll get the initial Elo rating of 1440. Is that correct?

On the other hand my national rating will be certainly less than that so what happens at that point: the national rating will be lifted up to the FIDE rating or the other way around?

P.S. I play in Italy.

I cannot answer your question about Italian rating, but I'm nearly sure that your national rating won't go up. They (FIDE and national) are separate rating systems and they shouldn't affect each other.

About the FIDE rating, it is regulated at http://www.fide.com/fide/handbook.html?id=172&view=article FIDE Rating Regulations effective from 1 July 2014. At article 8.2 you can check the exact formula.

8.2 Determining the Rating 'Ru' in a given event of a previously unrated player.
    8.21 If an unrated player scores zero in his first rated event, his score is disregarded.
    First determine the average rating of his competition 'Rc'.
    (a) In a Swiss or Team tournament: this is simply the average rating of his rated opponents.
    (b) The results of both rated and unrated players in a round-robin tournament are taken into account. For unrated players, the average rating of the competition 'Rc' is also the tournament average 'Ra' determined as follows:
        (i) Determine the average rating of the rated players 'Rar'.
        (ii) Determine p for each of the rated players against all their opponents.
        Then determine dp for each of these players.
        Then determine the average of these dp = 'dpa'.
        (iii) 'n' is the number of opponents.
        Ra = Rar - dpa x n/(n+1)
    8.22 If he scores 50%, then Ru = Ra
    8.23 If he scores more than 50%, then Ru = Ra + 20 for each half point scored over 50%
    8.24 If he scores less than 50% in a Swiss or team tournament:  Ru = Rc + dp
    8.25 If he scores less than 50% in a round-robin: Ru = Ra + dp x n/(n+1).

So, more or less, your initial rating will be your performance in your first tournament(s).


What is the maximum number of promoted pawns ever achieved in a competitive game? In theory, a player could advance all eight of their pawns to the end of the board, promoting them all. In my own experience, games with more than two promotions on one side have been vanishingly rare, and getting two promotions has been uncommon.

Has a player ever actually promoted all eight of their pawns? If not, what's the maximum number of pawn promotions that a player has achieved in regular competitive play?

In Tim Krabbe’s chess records, Krabbe gives a game where the Black player promoted four of their pawns, the most one player has ever gotten in a professional game, and only one where it has happened. It is also notable for being one of few games with 6 promotions.

The game can also be viewed here at ChessDB.com.

[Title "Alena Kubikova-Vaclav Novy, 9th Open, Czech Republic, 2003"]
[FEN ""]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3  g6 6. Be3 Bg7 7. f3 O-O 8. Qd2  Nc6 9. Bc4 Bd7 10. O-O-O Rc8 11. Bb3 Ne5 12. h4 h5 13. Kb1 a5 14. Bg5 Rc5 15. g4  hxg4 16. f4 Nc4 17. Bxc4 Rxc4 18. e5 Bc6 19. Nxc6 Rxc6 20. exf6 exf6 21. Nd5  fxg5 22. hxg5 Rc5 23. Nf6+ Bxf6 24. Qh2 Re8 25. Qh7+ Kf8 26. gxf6 Qxf6 27. Qh8+  Ke7 28. Rde1+ Re5 29. Qxf6+ Kxf6 30. fxe5+ dxe5 31. Kc1 Kg5 32. Rh7 f5 33. Rxb7  g3 34. Kd2 Kg4 35. Rb3 f4 36. c4 e4 37. c5 e3+ 38. Kd3 Rd8+ 39. Ke4 g2 40. c6 e2  41. c7 Rc8 42. Rc3 f3 43. Ke3 Kg3 44. Rc5 Re8+ 45. Kd2 Kf2 46. c8=Q Rxc8 47.  Rxc8 g1=Q 48. Rxg1 Kxg1 49. Rc1+ Kf2 50. b3 g5 51. a3 g4 52. b4 axb4 53. axb4 g3  54. b5 g2 55. b6 g1=Q 56. Rxg1 Kxg1 57. b7 f2 58. b8=Q e1=Q+ 59. Kc2 Qe2+ 60.  Kc3 Qe3+ 61. Kb4 f1=Q

Regarding informal OTB games, however, 5 promotions is the most that I currently know of from this game.

[Title "Manuel Matto-Anastasia Mossiaguine, Gibraltar Chess Festival, Gibraltar England"]
[FEN ""]

1. e4 e5 2. Nc3 Nf6 3. Nf3 Nc6 4. Bc4 Bb4 5. d3 O-O 6. a3 Ba5 7. Bd2 d6 8. h3 Bd7 9. b4 Bb6 10. Bg5 h6 11. Be3 Bxe3 12. fxe3 a6 13. O-O Qe7 14. Qe1 Ne8 15. Nd5 Qd8 16. Qg3 Nf6 17. Nxf6 Qxf6 18. Nh4 Qe7 19. Ng6 Qe8 20. Nxf8 Qxf8 21. Rxf7 Qxf7 22. Bxf7+ Kxf7 23. Rf1+ Kg8 24. Qg6 Kh8 25. Rf7 Rg8 26. Rxd7 b5 27. Rxc7 Nb8 28. Qxd6 Kh7 29. Qxe5 Kh8 30. Rxg7 Rxg7 31. Qxb8+ Kh7 32. Qb6 Rg6 33. Qxg6+ Kxg6 34. Kf2 Kf6 35. d4 Ke6 36. Kf3 Kf6 37. Kf4 h5 38. g4 h4 39. c3 Kg6 40. Ke5 Kf7 41. Kd5 Ke7 42. Kc6 Kd8 43. Kb6 Kc8 44. Kxa6 Kc7 45. Kxb5 Kd6 46. c4 Ke6 47. Kc5 Kf6 48. Kd5 Kg6 49. Ke5 Kh6 50. Kf5 Kg7 51. Kg5 Kf7 52. Kxh4 Kg6 53. e5 Kf7 54. d5 Ke7 55. c5 Kd7 56. b5 Kc7 57. a4 Kb7 58. a5 Ka7 59. e4 Kb7 60. a6+ Kc7 61. b6+ Kd7 62. c6+ Ke7 63. d6+ Kf7 64. Kg5 Kg7 65. e6 Kh7 66. Kf6 Kg8 67. g5 Kf8 68. h4 Ke8 69. h5 Kf8 70. g6 Kg8 71. h6 Kh8 72. a7 Kg8 73. b7 Kf8 74. c7 Ke8 75. d7+ Kf8 76. e7+ Kg8 77. e5 Kh8 78. e6 Kg8 79. e8=N Kh8 80. e7 Kg8 81. a8=R Kh8 82. b8=B Kg8 83. c8=R Kh8 84. d8=N Kg8 85. Ng7 Kh8 86. Be5 Kg8 87. h7+ Kh8 88. Nf7+


Trade a bishop in the opening In several openings white or black trades a bishop for a knight (Ruy Lopes exhange, Sicilian Rossomilo, Nimzo Indian etc).

I have learned the bishop pair is worth a half pawn, and I have difficult to understand these trades, which to me look bad. The opponents pawn structure get worse, but is this enough compensation for the trade?

In general there are two scenarios in the opening where one side might want to exchange one of their bishops for a knight.

The knight controls key squares in the center which are being
contested. In the Nimzo, for instance, the knight on c3 controls e4.
White would really like to put a pawn there. Pinning and then
exchanging that knight makes the e4 pawn push far less likely.
Similarly in the Dutch black sometimes plays Bb4 to pin the knight on c3 to weaken white's control of e4 and will swap if a3 or O-O is played.
Where one side has control of most of the space on the board that normally gives them an advantage because they have more room to manoeuvre their pieces and can switch the point of attack more easily. The side with less space, conversely, often struggles. However there is balance between space and number of pieces. More space with lots of pieces confers an advantage. Reduce the number of pieces and the pawns defending that space become overextended as the few remaining pieces struggle to defend them. Similarly a cramped space with lots of pieces becomes a comfortable one when pieces are exchanged. So, again, in those positions it is often worth one side exchanging a bishop for a knight.


What are some of the best free puzzle rush apps? I'm looking for a puzzle rush app that's free and does not require a subscription. I tried using the Chess.com app, but there's a limit on the number of times you can play in a day.

Check out https://blitztactics.com/ which is pretty much the same thing.
It even has a few other modes.