Free software for intermediate learner? I'm at about 1600 level, roughly speaking, and I need a good software with lots of options to keep me interested in learning chess and improving myself.  I've heard of different ones, including SCID, Lucas, Arena, and recently someone recommended Jose.  Do you know of any other programs or what do you think of these?  I'm not computer literate so please dumb down the explanation for me.

For instance, someone said that Arena is closed source but SCID is not, and that SCID is more of a database program.  I don't know what those things mean or if that makes one better than the other.  Jose was someone's solution on a website to someone wanting to combine the best of SCID and Arena, for instance.

Thanks

Why not solve more Chess puzzles? That will definitely help you.
There are many freemium model chess sites out there..

My favorite is Chessity
Others in this list are:

Chess.com
Chess Tempo

[This list is endless. Other may have suggestions too.]

I'm afraid that playing against computers might defeat your motivation, because they are very good and beat humans without mercy.

I would also recommend playing online with other human folks.
I use Playchess


Understanding the x-ray tactical motif? Can someone explain the x-ray tactical motif?  I have looked at this example, but I still don't understand it fully.  If you can provide other examples, that would be great too.

Basically, if a defending piece of your opponent has one of your pieces with the same movement "behind" it, then it's not really defending anything, as your piece standing behind also "attacks" what you want to capture through that defending piece of your opponent's.

In the following exampe, the ♞g6 is x-ray-attacked by the ♖b6, through the ♜d6, so once the other rook takes it, it is defended through the black rook by the ♖b6 (and the knight is lost).

[FEN "7k/4p3/1R1r2n1/P7/6R1/8/8/7K w - - 1 1"]

1. Rxg6


What are some beginner opening variations after an opening has been chosen? I have seen a ton of questions on how to choose an opening repertoire, but I haven't really seen anything on once you choose an opening, are there specific variations that one should start off with that are easier than others.  I will use the French Defense as an example.  Every time I played the French Defense, I instinctively played 3.e5 (The Advanced Variation), but it was pointed out to me by stronger players that as a beginner, I should try to stay away from the Advanced Variation for now and stick to theMain line3.Nc3or The Exchange Variation3.exd5 exd5`.  Is the above true regarding the French Defense?  What variations of other openings are usually good for beginners to learn?

I would say that it almost does not matter. I think that anyone under 1700 USCF will get far more out of the study of the basics of the opening phase of the game and the general strategic ideas of the specific opening she or he has chosen. From a practical perspective it is too difficult to say what you are going to get 13 moves into an under 1600 USCF game to really dedicate too much time to an opening.

So the exact variation simply does not matter at the beginner level (assuming that is players under 1400 USCF). Notice in my terminology I consider a novice to be someone completely new to chess who has never played in a tournament and really only knows how the pieces move and the basic rules. I distinguish this from a beginner who knows a bit more about chess, may have played in a tournament, has a rating under 1400 USCF as mentioned before. I know these terms are generally synonymous but I think that it's important to distinguish between these two types of "beginners".

So my suggestion would be that at the beginner level one just shouldn't be too concerned about picking the exact variation but instead dedicate more time to learning about the general ideas of more openings by studying GM games from a variety of openings in addition to the openings you have chosen to play and keep your memorized book to a minimum.

Here are some suggestions on how to study the opening from Dan Heisman:
http://www.chesscafe.com/text/heisman37.pdf

  When a player first starts out to learn the openings, he gets the most
  efficient use of his time by learning:

  General opening goals and guidelines,
  A few main opening sequences (tabiyas), and
  How to avoid making the same mistakes over and over.


What is the purpose of 3...a6 in the Ruy Lopez? It doesn't kick the bishop off that diagonal, and playing ...b5 later puts the bishop on another great diagonal and is supposedly bad for black (an explanation of this would be great too). So why is 3...a6 in the main line for black?

[FEN ""]
1.e4 e5 2.Nf3 Nc6 3.Bb5 a6

Playing ...b5 later is not bad for black. Playing it immediately isn't so great, but Black almost always plays ...b5 at some point (unless White plays Bxc6 first!).

The main reason to play ...a6 early is that you can now play ...b5 any time you want to if you decide that you don't White to take the knight on c6. If you don't play ...a6, and then later decide that you want to kick the bishop away and start by playing ...a6, White can go ahead and play Bxc6. If you've already played ...a6, you can go straight to ...b5 and White doesn't get a chance to capture your knight in response.


Players that have trouble finishing Some players have trouble converting a winning position, perhaps even blowing it. As the strength increases, these "winning" advantages become smaller and more subtle.

How does one "finish" in chess? Is it about defense, or having a strong attack?

Id' reckon converting an advantage into an actual win has a lot to do with keeping in mind that a position is worth nothing unless you are there to steer it accurately towards victory. Otherwise it's very easy to be visited by 'the ghost of the won position', which would try to convince you that you can relax before the game is over, trying to trick you into making unneccessary mistakes which would diminish your advantage.

When you write "finish" I interpret that as "converting a big advantage into a win". Is this a correct interpretation? If so, then it all depends on the position at hand; if your opponent played an unsound sacrifice for an attack you may have to defend, while if your opponent played too passively you may have to attack to accurately steer the game towards its logical conclusion.


Are there ever scenarios where more pawn islands are preferred? In chess, it is usually advisable to have fewer pawn islands than your opponent. However, while I was watching a youtube video by someone called agadmator chess, he mentioned that multiple pawn islands do have their benefits and I'm trying to understand what kind of benefits or scenarios where multiple pawn islands are an advantageous factor.

Such scenarios arise occasionally in the late endgame.  For example, this position is a win for white (LiChess):

[fen "1k6/8/8/7p/P2P2pK/8/8/8 w - - 0 1"]

while a similar position (where white has fewer pawn islands) is a draw (LiChess):

[fen "1k6/8/8/7p/PP4pK/8/8/8 w - - 0 1"]

In the first case, if black's king captures a pawn, the other white pawn promotes (although white needs to play precisely).  In the second case, black's king can stop both from promoting because they're closer together, i.e., because of there being one pawn island.


Great Chess match resources (PGN) suggestions anyone? Using Arena with a number of Chess engines, I love configuring Arena to use its 'book' feature.  There are books of openings, books of famous games, books of particular players, surprise wins, etc.

Therefore I'm constantly on the search for PGN resources, such as the ones found here:

Historic Tournament Matches
Particular players

Question:

  Can anyone recommend specific "must have" PGN files OR PGN sites where such files may be downloaded?

Recommended files or sites should be:

Well organized
Correct
Comprehensive or complete
Noteworthy

The first site I'd recommend is Chessbase:

This site has a massive searchable database containing over 8 million games, including very recent matches, meaning at the time of this post 2016.  The interface is very well designed and feature rich (such as presenting per move statistics).  The site's authors do a reasonably good job of establishing comprehensive sets by pursing all extant copies of a particular player or tournament.

Although this database is essential, the site's features favour those who log in.  The basic account is free, and it's credentials are accepted at sister sites, however to getting PGN of particulars game you need a premium account.

  The second, more historical site to check out is ChessGames:

This site's vast database of historical chess games has over 812,000 games, all searchable via the sites Search feature.  Many of the not-so-recent historical games can be found in this gem-of-a-site.  That said, the games are accessible in PGN format one at a time.

  The third site to checkout, more specialized, is 365Chess:

Many players have seen as high-profile sponsors of top calibre competitions, or great match GM commentators. Accounts are free to create, and the site has other useful features such as the "Chess Opening Explorer" which allows you to create notes for particular openings (useful for study).

Also, the site presents a subset database of openings by players of 2400 ELO or more. The games included in the Masters Database are also part of the Big Database, but if you search or browse the database you'll obtain only games of the most talented masters.  This database is called "The Masters Database".

Another really nice feature is the ability to download all games by a particular player, but this feature requires a full membership, so not available to the free hobbyist.

  The fourth site to check out is PGN Mentor:

This site freely gives away complete sets of PGN games for specific players.  They download as .zip files.  Likewise, the site gives you the ability to download compilations of games categorized by opening. The sets you get aren't entirely current, and the sets not always complete (meaning important games for examples are left out), however they are free and generally pretty good.  That makes this site invaluable!

  Finally, check out Mark Weeks collection:

This is another recommended site with surprising curiosities such as Kasparov vs. IBM's Deep Blue and very early (historical) games.  The site is not fancy looking but nicely organized grouping by "Pre-FIDE" and "FIDE".  It claims to have millions of games, but honestly, I haven't yet given this site the attention it merits to get a sense of this.

  A recommendation that came from a read is This Week In Chess

This site keeps you up to date by delivering you Weekly updates, specifically, daily Chess news and games are in this weekly digest for download, by Mark Crowther. The site says "Every Monday The Week in Chess covers all the latest news and games from international chess. Download the zipped file of games in PGN or ChessBase (cbv is the modern format) format for reading off-line."

  If you have other recommendations and 'must have' sites that provide PGN resources, please


Queenless Imbalanced Middlegame(2) I analyzed the following position with both Stockfish 10 and Komodo 13.2. The 2 monster engines evaluated it at a dead draw at 0.00. Is this really the case or does either side have some sort of an advantage? Notice that in the position black is up 2 pawns although they aren't pawns to feel happy about. White has the bishop pair and a rook on an opening file. Compared to black's rook which is undeveloped. I would also be interested to know what is a neural network's(Leela) evaluation of the position is any of you have it downloaded.

My take: White is down 2 pawns, but he has the bishop pair, and black's pawn structure on the queenside is deteriorated. White also has a very active rook which can maneuver itself between the 2 open files to exert pressure. However, the main idea that I noted was the there are 2 open files so black can play King f7 and bring the rook over one of them. Perhaps the biggest compensation that white has is the massive space advantage due to the strong center. My take is that it should be equal, but can someone explain it better because the engine might not be right?

White to move

 [FEN "4k2r/p1p1n2p/B1p1bpp1/8/4PP2/B7/6PP/3R2K1 w k - 0 1"]

My initial impression was that in a practical game, white would win.

If it were not for the plan that the computer found, my impression would be that Rb1-b7, and winning back one pawn, with the remaining weak pawns, white would then likely win back the second, and just be clearly better. White is also ahead in development, and has an incredibly strong bishop pair, as you mentioned. Lastly, if the black king went to f7, as soon as it did, if white could take on c7, the Rh8 will be forced to go to e8, and it will be hard to break that pin. This would be very bad. I had a position once as white that could have ended up in this dream scenario, but my opponent played differently, and I ultimately won tactically instead. That game definitely influenced my initial, and shallow, assessment of the position. My initial, cursory, assessment was wrong.

Now, that I turn on the computer, it took the wind out of my idea immediately, and it is a likely draw for one reason: It is a positional standoff, and immediately, which white should force. With the Rb1 plan, which Stockfish 11 thought was best, black threatens to play Kd7 and Nc8, which defends everything. As soon as black plays Kd7, white needs to play Rd1 forcing the king back, and then can return to b1 with the same threat forcing a repetition. If black does not find that plan, white likely wins, but frankly, it would not be hard for a strong player to find. My initial thoughts were just from a quick glance.

White can try to move around, and induce a black mistake; but there are also many more pitfalls for white than black, and white could also make a mistake. You can never lose sight of the fact that you are two pawns down, and must be careful that there may be a defense that will leave you begging for a draw…if you are lucky.

The evaluation of the position is such:

Black has two pawns, and that is really the major redeeming quality of the position from black’s perspective. It helps that the weaknesses are close to home, which usually makes them more defendable, and the king is close enough to help with that. The white bishops are a bit unfortunately placed for a Bc5xa7 idea due to the move Ra8 winning, so it will take at least an extra move for that plan to work. Black has the possibility of Kd7 and Nc8 holding it together if Rb1 by white, and even with the potential loss of a7, black is up a pawn with a compact structure. White must be careful not to overplay his hand, or the extra pawns could become decisive. The Nc8 is the hero of black’s defense.

White has the two bishops, and a very weakened black queenside to go after. The Rd1 is more active for now, and the Rh8 is out-of-play for now, but might get out in time. The Kg1 is going to be the more active king. It is very important that the Pe4 takes the squares f5, and d5. especially, away from the black pieces. Black is, clearly, on the defensive.

With such a material imbalance, it comes down to very concrete calculation, which computers are particularly good at, and I believe the evaluation; however, there is room for both sides to play on, but to do so leaves the game on a razor’s edge. Black could slip up, and white’s activity could be decisive, but if white is not accurate, the material could have the last word, and from the lines below, this is the more-likely scenario.

The obvious plans for white are Rb1-b7, Bc5 and trying to capture on a7, and bringing the K to the center or queenside via d4 can c5 (it turns out that this is a fantasy though). Some of these might combine with a plan of Bb7-c6. Black’s plans are mostly reactionary to whatever white plays, but some are based on f5, securing the d5 square, or Nc8-d6 or b6.

After seeing the variations below, white easily has enough activity to compensate for the two-pawns deficit, but as the variations show, mostly due to the incredibly well-placed Ne7-c8, no more. To play for more is risking having to play a long defense for white.

In conclusion, I found many positions that white was either worse, or losing outright, but none that white was better. After analyzing this in depth, it is my opinion that with best play, white has absolutely nothing, and has a significantly higher risk of losing than black does, which I found counterintuitive and surprising.

After looking at the lines, as long as black sees the Kd7 and Nc8 plan in response to Rb1, which is fairly easy, he has no risk of losing. After looking at the lines, based on my years of experience, between two strong players, I did not see any moves that were particularly difficult for black to find. White should force the draw.

 [FEN "4k2r/p1p1n2p/B1p1bpp1/8/4PP2/B7/6PP/3R2K1 w k - 0 1"]

 1. Kf2 {It is the Kf2 plan that offers white the least losing chances.} (1. Bc5 {The Bc5 plan.} Kf7 $15 {For example.} 2. Rb1 Rd8 3. Kf2 (3. Rb7 $2 Rd1+ 4. Kf2 Rc1 5. Be3 (5. Bxe7 Kxe7 6. Rxc7+ Kd6 7. Rxh7 Ra1 8. Bf1 a5) 5... Rc2+ 6. Kf3 Bc8 7. Rxa7 Bxa6 8. Rxa6 Rc3 9. Ke2 f5 10. Kd2 (10. exf5 Nxf5 $17) 10... Rc4 11. exf5 Nxf5 12. Ra7 Ke6 13. Rxc7 h5 {And although equal, black is to be preferred.}) 3... f5 $1 4. Rb7 Rd7 5. e5 Nd5 6. g3 Nc3 7. Ke3 Nb5 8. Bxb5 cxb5 9. Rxa7 (9. Rxb5 $2 Rd5 $15) 9... c6= {But why would white want to play for this?}) (1. Bb7 $2 {The Bb7 plan immediately is just too slow.} Bc8 $1 (1... Kf7 {Is also good.} 2. Rc1 Bd7 3. Ba6 Re8 4. Bc5 f5 5. exf5 Nxf5 6. Bxa7 Ra8 7. Ra1 $1 Nd6 8. Bf2 Be6 $15) 2. Bxc8 Nxc8 3. Bb4 {Only move, and try to figure out why OTB.} Rg8 {Preparing to activate the rook, and black is better. There is no need to continue the analysis as it is clear that black is much better placed than at the beginning when white still had the two bishops, so white should have just forced the repetition.}) (1. Rb1 Kd7 2. Rd1+ {And white can force the repetition.} (2. Rb7 $6 {First, the Rb7 plan, which is trying to push too hard, and black is already at least equal.} Nc8 (2... Ra8 {Is also possible with the idea of Nc8-d6 or b6.} 3. Bc5 Nc8 4. Rb2 {And white is already forced to retreat or see the Rb7 get shut out of play, and maybe later, trapped.} Nb6 5. Rd2+ Ke8 6. Bb7 Rb8 7. Bxc6+ Bd7 8. Bxb6 Bxc6 9. Bxc7 Rb1+ 10. Kf2 Bxe4 $15) 3. Rb8 {Already having to bail out.} (3. Bc5 $4 Nd6 4. Bxd6 {Almost forced since e4 hangs.} (4. Rb4 Re8 {And black is winning now, and free. E4 is very weak.} 5. e5 fxe5 6. fxe5 Nf7 $19 {And d5 is now available for the Be6.}) 4... Kxd6 5. Rxa7 Rb8 6. Be2 Rb2 $17 {With a huge advantage that is almost winning.}) 3...Rd8 {Forcing white to bail out into the worse side of the draw, for example...} 4. Bxc8+ (4. Kf2 $2 Nb6 $17) 4... Rxc8 5. Rxc8 (5. Rb1 $2 Re8 {Again, aiming at e4.}) 5... Kxc8 6. Be7 f5 7. e5 Kd7 8. Bc5 a5 {Still equal, but why go for this when there is much easier?}) 2... Ke8 3. Rb1=) 1... Kf7 (1... Nc8 2. Rc1 Kd7 3. Rd1+ Ke8 (3... Nd6 $4 4. e5 $16) 4. Bb7 Bd7 5. Bc5 $2 Nd6 $1 6. Bxd6 cxd6 7. Rxd6 Ke7 8. Rd1 a5 9. Ra1 Rb8 10. Ba6 c5 $1 11. Rxa5 $4 Ra8 $19) 2. Rb1 (2. Bc5 $2 f5 3. exf5 Nxf5 $17 {And black has solved all his problems.}) 2...Rd8 3. Rb7 {There are too many lines to give them all, but black has no problems.} Rd7 4. Rxa7 f5 5. e5 Nd5 6. g3 Nc3 7. Bb4 Ne4+ {Or Nb5 or Nd5.} 8. Ke3 c5 9. Ba5 c6 10. Rxd7+ Bxd7=


Magic Bitboards, Feeding in Randoms - Why have to find magic instead of just loading from disk? I read about Looking for Magics for Magic Bitboard, they mentioned the method "Feeding in Randoms".

As I understand, this method works like this:

label RETRY;
magic = random();//trial

for (all cases of current square: from first case to last case)
{
  if (magic fails at any case)
    go to label RETRY;//and error
}
//Passed all cases -> success! now we have the magic for square 1, 63 more squares to go

The author said

  On my Core Duo 2.8 GHz, it takes less than a second to find magic numbers for rooks and bishops for all squares

If we successfully get magic numbers with this "Randoms" method, why not just save the magic numbers to disk and load it from disk instead of running the "Feeding in Randoms" code every time at startup (that the author cares about how fast this method, isn't it faster just read the magic from disk instead of trial and error with random. If load from disk, it doesn't matter if the method takes whole day to find magic)?

Maybe I misunderstand something about this. So I want to ask Why have to find magic instead of just loading from disk?

Computing magics at statup is fine because it's done only once and not very slow.

  https://github.com/official-stockfish/Stockfish/blob/master/src/bitboard.cpp

// init_magics() computes all rook and bishop attacks at startup. Magic
// bitboards are used to look up attacks of sliding pieces. As a reference see
// www.chessprogramming.org/Magic_Bitboards. In particular, here we use the so
// called "fancy" approach.

Stockfish did it. Leaving the constants in the code is also fine. It's all about implementation.


Jaenisch/Schliemann Gambit Is the Jaenisch/Schliemann Gambit being played or it has become out of fashion?

PS: I am a club player (FIDE ~1800) and occasionally use it to success.

It depends what level you're talking about.  At the top level with super GMs, it's more or less out of fashion in serious games.  They either choose the Berlin or some other main line (like the Closed Spanish).

In the -2000 section though, it's still a viable opening.  If you know it well enough then it's a good weapon to catch your opponents off guard.  I would recommend learning another line to play against the Spanish though, so that you can alternate between it and the Jaenisch.  If someone were to spend a serious amount of time preparing for you, they could cause some problems.  If you have multiple lines though, it makes preparation much more difficult.

I looked up the Jaenisch's stats in the Mega Database, and it actually stores fairly well.  White only scores slightly over 50%, and this is a normal stat for most main lines.  Also, some top level guys have played it before (Aronian, Radjabov, Carlsen, Ivanchuk).  While they don't play it regularly, it's still a testimony to the viability of the Jaenisch.


Are there any free chess engines that can be used to analyze online or in a mobile phone? I want to analyze chess games. Is there any reliable chess engine that is free

Please specify your mobile platform in your question.

On the iOS platform, I recommend my own apps for doing that. www.smallchess.com.

Otherwise, there're lots of possibilities. If you can narrow your focus, I'll edit my answer.


Node Cap for Stockfish I discovered something quite unusual when working with stockfish 10 chess engine in arena. The discovery leads me to ask: Why does Stockfish_10_x64 have a Node Cap when searching moves based upon amount of Nodes used?

To play a position, an engine is usually given a search depth. Arena always does this. Probably in your case the search depth was set to a limited number of nodes. You can check this by keying in CTRL+L. The adjust level box pops in. There, you can see how the depth was specified, whether a time limit, a nodes limit, a search depth limit or an infinite depth.


How to study endgames? There are lot of recommendations on what endgame books you should read and study. But reading is just passive learning, and not so efficient.

If the book doesn't contain exercises, what is the best method for active learning and doing exercises?

One idea I have is to play the positions against an engine. Are there better suggestions?

Personally, I love a number of great books, and there is still no substitute. You can then plug positions into a computer to test yourself.

I still love Fine's "Basic Chess Endings". Despite the errors, many corrected later in the Pal Benko edition, it gives a great sense of WHAT you are trying to accomplish in any type endgame. Simply by reading over all the examples, and the sub-examples, you will absorb a lot. Each sub-example, while meant to show an exception, or other deviation, is also reinforcement of the main idea.

For example as to my comment about "WHAT" you are trying to accomplish, take a minor piece endgame where you are up a pawn. The basic plan is to create a passer, and if your opponent blocks with the K, you run with your king to attack and take his other pawns. It he just tries to block it with the piece, you run over and force him to give up the piece for the pawn.

I studied this book when I was rated just 1036, and much of what I learned has stuck with me through being a Master almost 40 years later. No less than World Champion, Mikhail Botvinnik, considered it the best book on the endgame (although many greats ones have come along since). Fine's words are chess gold.

Next, I really like "100 Endgames You Must Know: Vital Lessons for Every Chess Player" by GM Jesus de la Villa. Not many books get a fourth edition, which is a testament to this book's appeal. In addition, he recently added "The 100 Endgames You Must Know Workbook: Practical Endgame Exercises for Every Chess Player", which lets you apply the 100 endgames from the first book in practical game exercises.

Lastly, if you really get strong, I still consider "Dvoretsky's Endgame Manual" THE single most instructive book ever written. That said, it is not for novices, and expects a lot of prior endgame knowledge. Similar to de la Villa's recent workbook, Dvoretsky also wrote "Tragicomedy in the Endgame: Instructive Mistakes of the Masters", which shows practical games involving information from DEM.

No matter what you do though, endgame study requires time and effort; however, unlike opening study, this study will stick with you for a lifetime.


Why is castling through and out of check prohibited? Why is castling disallowed when the king is in check or when the square the rook will be placed on is under attack?

What is the rationale behind this ruling?

One rationale that I can think of for not allowing the king to move through check parallels that behind the possibility of capturing en passant after a pawn makes a two-square advance.

The typical pawn move is just a single square forward, and the possibility of advancing two squares on a pawn's first move was a relatively late addition to the game in historical terms. Since the "nature" of a pawn had long been to make a single square advance, when that new sort of pawn move came into being, the en passant capture was a natural counterpart: the pawn doesn't "jump" two squares ahead, but rather "marches" through the intermediate square, and an opposing pawn is thus allowed to capture en passant on the following move if it is in position to have captured the advancing pawn at the intermediate square.
With that explanation in mind, let's consider your rule. Like pawns, a king's typical, natural movement is only a single square in distance. And like the pawn's two-square advance, castling is a relatively new addition to the rules of chess that is intended to speed the game up. So just as the en passant capture reinforces the pawn's nature as a one-square mover, the rule prohibiting a king to castle through a checked square reinforces the king's nature as a one-square mover. He is thought of not as gliding over the checked square, but rather trudging through it. And just as an opponent's pawn has a chance to capture en passant, an opponent's piece guarding the intermediate castling square would be given the right to capture the king. Since that's not a legal part of chess, castling through check in the first place isn't either.

As for why castling is disallowed just because of the king being in check, I'm not so sure, but I'll speculate. If, in the analogy between chess and war, we think of a check to the king as a wounding attack, less severe than the lethal checkmate but damaging nonetheless, then it's reasonable to insist that the hobbled king can't make a swift, immediate escape via castling. But maybe that's just how I think of it.


Why was 50 chosen for the 50-move rule? The reason for the 50-move rule, along with the triple-repetition rule is to make chess definitely finite. How did one arrive at the number 50? What would change if it was 40 or 60? Is the number 50 chosen carefully?

At one time, it was believed that all winnable endgames could be won
  within fifty moves. However, in the early twentieth century, some
  exceptions were found, including A. A. Troitsky's (1866-1942) analysis
  of the two knights endgame as well as the endgame of a rook and bishop
  versus a rook. The rules of chess were revised several times to admit
  exceptions to the fifty-move rule for certain specific situations.
  Early on, the fifty-move rule applied to tournament games but not to
  match games (Troitzky 2006:197).

SOURCE: Fifty-move rule


A 50-move-rule claim turned out to be incorrect - can the arbiter punish me? I claimed a 50-move draw, but my claim turned out to be incorrect. Can the arbiter punish me by increasing the opponent's time or reducing mine?

Yes
According to the FIDE Laws of Chess

9.5.3 If the claim is found to be incorrect, the arbiter shall add two minutes to the opponent’s remaining thinking time. Then the game shall continue. If the claim was based on an intended move, this move must be made in accordance with Articles 3 and 4


Can a KB vs. KB endgame be declared drawn if a checkmate can occur and the 50-moves-rule doesn't apply in a Blitz game? Bishop and King vs Bishop and King, with opposite-colored bishops, is usually a draw unless a serious blunder happens.
[FEN "8/8/8/3b4/8/7k/8/6BK w - - 0 1"]

What is the requirement for an arbiter in the below position if one party is seriously on time trouble say 2 mins against 15 seconds in a blitz tournament if this party claims a draw?
If the arbiter happens to notice this position, can they call it a draw before the 50 moves rule is reached?
[FEN "8/8/8/1B2k3/3b4/8/3K4/8 w - - 0 1"]

What is the requirement for an arbiter in the below position if one party is seriously on time trouble say 2mins against 15seconds in a blitz tournament If this party claims a draw?
If the arbiter happens to notice this position, can they call it as
draw before the 50 moves rule is reached?

No. Helpmate is still possible hence the arbiter cannot intervene.
This applies with any increment and always in blitz.
The relevant article in the latest FIDE Laws of Chess is:

5.2.2 The game is drawn when a position has arisen in which neither player can checkmate the opponent’s king with any series of legal moves. The game is said to end in a ‘dead position’. This immediately ends the game, provided that the move producing the position was in accordance with Article 3 and Articles 4.2 – 4.7.

The relevant section about quickplay finishes is now -
Guidelines III. Games without increment including Quickplay Finishes
The key parts say this:

III.2.1 The Guidelines below concerning the final period of the game including Quickplay Finishes, shall only be used at an event if their use has been announced beforehand.
III.2.2 These Guidelines shall apply only to standard chess and rapid chess games without increment and not to blitz games.


Standard endgame chess positions which are helpful to learn Is there a list of standard endgame chess positions which a player can benefit from learning? By this I mean that any player should know how to play KQ vs K, KR vs B, KP vs K (win if it winnable and draw when it is not).

Then it goes KBB vs K, KRP vs KR and then on higher level KQ vs KR, KR vs KN, KBN vs K. These are just some of the end-game positions which might be helpful to learn.

Do you have other positions which could be helpful (and may be approximate level when it makes sense to learn them)?

For sure KP mixes like KP vs KP, KPP vs KP etc: learn to count moves to promotion, study opposition and zugzwang.

Later KRP+ mixes: like KRP vs KR till KR4P vs KR3P are all quite common, far more relevant than say KBN vs K, not easy though, especially 4 vs 3 pawns.

A bit less common KNP+ and KNB+. still relevant.

Finally endgames where one side has a piece and the other only pawns: this are quite common at lower levels.


Configuring TheWeekinChess downloads with Megadatabase 2014 This quite a technical question, anybody who knows about the program Chessbase (12) and how it works please feel free to answer.

Recently I downloaded many PGN files from the website The Week in Chess,

I copied all of the games (over 100,000) into my current unedited version of Chessbase Megadatabase 2014, the games were installed successfully.

The problem is that when I do the 'Opening Report' and the player 'Dossier', I find that my TheWeekinChess download games are ignored, I know this because all of the TheWeekinChess downloads are games from 2014 and none of these are shown in the Opening Reports (main lines) and player Dossiers (top players).

For example, I input the moves 1.e4 c5 (Sicilian), click Opening Report and it works but the latest games are all played in 2013 even though there are games from the year 2014 in the database.

I search for a player in the Player Encyclopedia, for example: Magnus Carlsen, I click dossier and it works perfectly fine; but then again the games go no further than 2013.

Could anyone show me a way to solve this problem?

The Mega Database 2014 is in chessbase format and contains not only the games but several pre-requisite to all options proposed by Chessbase 12.
So by using pgn files, you will find the games in your database but they are not optimize for the others options.


What are the sites and links to get a FIDE rating? I am an active member of Chess.com. Now, I want a FIDE rating. Are there any possibilities that with reference to the Chess.com rating, I can get a FIDE rating? Since I am new to this please provide me a clear suggestion.

Chess.com is a private organization that is not affiliated with FIDE (the World Chess Federation). Also, Chess.com's ratings are based on online play (and so unofficial), whereas FIDE only rates official, over-the-board tournaments. So it is not possible to get a FIDE rating based on Chess.com rating.

You can get a FIDE rating by playing in a tournament that will get rated by FIDE.


Queen's gambit declined: is it too late to counter-offer my c pawn if white pins my f-knight? Will this overload my f bishop? In the traditional queen's gambit, white offers their c pawn to the e5 pawn, threatening to take back with their f bishop and enjoying a central pawn advantage. My response is to play symmetrically, that way I can learn how to play it by defending against it first, so I reject the c pawn and offer my own pawn on c5 in response. I also like to place my knight on c6 after that.

A  common opening theme is for a bishop to pin a knight and a royalty piece, inhabilitating the knight and threatening to double up a pawn thus weakening the castle pawns. My tipical response is to block with my bishop.

Is it possible to respond to both of these threats simultaneously in the same way that I respond to them individually? This is important because it would simplify my opening book significantly. The main challenge is that the f bishop is overloaded with the task of defending the thematic c pawn and the f knight.

Consider the following game:

 [FEN ""]

 1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Bg5 c5 5. e3

I would ideally delay c5, but I want to keep the example simple here. My dilemma is, how do I develop my f bishop? I can't move it to d6 because after:

 [FEN ""]

 1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Bg5 c5 5. e3 Bd6 6. dxc5 Bxc5

I would have wasted a turn moving my bishop twice in a row, and I would have to waste another one if I ever want to move my queen or protect against a Knight attacking my f6 knight.

I can't move my bishop to e7 either because after:

 [FEN ""]

 1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Bg5 c5 5. e3 Be7 6. Nc3 O-O 7. Bxf6 Bxf6 8. dxc5

And recapturing that pawn seems very awkward, all pieces are 2 moves away, and c5 is not a particularly good place for any piece to be, especially if cxd5 and the c file is open for white's a rook. At any rate the main theme of the opening is broken.

My best answer so far is to play b6, so that my c5 pawn will have 2 defenders. If after c5 my opponent immediately takes my pawn, I recapture with my bishop,

 [FEN ""]

 1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Bg5 c5 5. e3 b6 6. dxc5 Bxc5

However if I my bishop had already developed to its knight-guarding spot, I take with my b pawn.

 [FEN ""]

 1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Bg5 c5 5. e3 b6 6. Nc3 Be7 7. dxc5 bxc5

There are a lot of different defenses to the Queen's Gambit Declined, but in most of them, you do not need to worry too much about white trying to take on c5, and holding it since it is very difficult to keep in most lines.

I am going to post some basic lines that lead to different variations, and some comments about each. This material will give you a very basic look at how you can play as black, and if you choose a line, I would gladly expound upon it, but the topic as a whole, can cover entire books. I mention the Ragozin with Bb4, for example, and I recently got a 351-page book on that one line alone.

There are a lot of notes to the moves, so make sure you read those as you go through this in the viewer.

 [FEN ""]

 1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Bg5 c5 {If you play an early c5, then white might opt to give you an isolate pawn, and force you to play the Tarrasch Defense, which scores a sky-high 73.5% for white in the Mega 2020 database.} (4... Bb4+ {This is the Ragozin Defense, which also has drawbacks like giving up the bishop pair, or certain structural weaknesses, but in exchange for piece activity. Note that had white played the move order with 3.Nc3, white also has the option of Qa4+ since Bb4 is not check, thus it would force Nc6 blocking the c7 pawn.}) (4... Be7 {The traditional QGD, where black completes development, and only then is prepared to hit back in the center with c5, or play other lines with the freeing Ne4, or cxd4. In this line, you need to be prepared to play the Exchange Variation, which is very popular at the club level, and leads to the minority attack.} 5. cxd5 (5. e3 O-O 6. Nc3 Nbd7 7. Rc1 c6 8. Bd3 dxc4 9. Bxc4 Nd5 10. Bxe7 Qxe7 {Is one of the lines, for example.}) 5... exd5 6. Nc3 c6 7. Qc2 O-O 8. e3 Nbd7 9. Bd3 Re8 10. O-O Nf8 11. Rab1 {Preparing the "Minority Attack" (attacking the majority of pawns on the queenside with a lesser number) with b4-b5, weakening the black queenside.}) 5. Nc3 (5. cxd5 exd5 6. Nc3) 5... Nc6 (5... cxd4 $1 6. Nxd4 Be7 (6... e5 $1 {This is very active, and scores well for black with white winning only 42% of the time per the Mega 2020 Database. It would require learning a fair amount of theory though.}) 7. e3 O-O 8. cxd5 Nxd5 9. Bxe7 Nxe7 10. Be2 Nbc6 $14) 6. e3 Be7 7. dxc5 {This is a main line, but you do not need to capture back with the bishop right away.} Bxc5 {The line you gave.} (7... O-O $1 8. cxd5 (8. Qc2 $1) 8... exd5 9. Be2 (9. Bxf6 Bxf6 10. Nxd5 Bxb2 11. Rb1 Ba3 {And black will get back c5 with a good game, but white is still slightly better.} 12. Bd3 $1) 9... Be6 10. O-O Bxc5 11. Rc1 {With a typical Tarrasch.})

It was starting to get too deep for one board, so I put the answers to your edited question in this board. Again, make sure you look at the prose that is include with the various lines.

 [FEN ""]

 1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Bg5 c5 {I feel like this is just too early for my solid style.} 5. e3 Be7 (5... Bd6 6. cxd5 exd5 7. Nc3 Be6 {And having moved the bishop twice is not that big a deal, but you have to be prepared to play the Tarrasch which requires good opening preparation due to the fact that you have the isolated pawn, and you need to know how to get the piece activity that is associated with it. I have a student at the high school club that I run, who plays this all the time, but I have been telling him lately to avoid it since it does not fit his style. If you are a player, who likes very complicated open positions and play 1.e4, the Tarrasch might be for you.}) (5... b6 $4 {A positional blunder since it wastes too much time, and weakens the light squares heading toward the king. It is almost losing since your king is not developed.} 6. cxd5 Qxd5 (6... exd5 7. Bxf6 Qxf6 8. Nc3 {And there is no good way to defend d already.} Be6 $2 9. Bb5+ {The light squares come into play.} Nd7 10. dxc5 (10. Bxd7+ Kxd7 11. dxc5 Bxc5 12. Nxd5 Bxd5 13. Qxd5+ Kc7 14. O-O $18) 10... bxc5 11. Nxd5 Qxb2 12. Rb1) 7. Bxf6 gxf6 8. Nc3 {With a winning position.}) 6. Nc3 O-O 7. Bxf6 $2 {Giving up the bishop pair since you cannot really win c5 is not good. Black will give it back, and you will have a huge weakness on c3 on an open file.} Bxf6 8. dxc5 $2 {This makes it worse.} Bxc3+ 9. bxc3 Qa5 10. Rc1 dxc4 11. Bxc4 Qxc5 12. Qd4 Qe7 13. O-O Nd7 14. Rfd1 Nc5 15. Ne5 b6 {With the slightly better position after Bb7, and the rooks coming to the center.}


How is a computer programmed to play chess? How is a computer programmed to play chess? What are the ways by which they sort out the moves? My question is not about programming but the idea behind programming to play chess. That can really help me in chess.

Chess programming is full of "rules of thumb" that can be applied to your own chess.  There are many aspects to chess programming... but the most prominent are tree search and a heuristic evaluation.  Here are some ideas that you might be able to apply to your games:

Minimax Search: The basis for adversarial search formalized... I'd hope the principle here was intuitive.
Evaluation: A computer scores a position by combining metrics about material balance, king safety, activity, and pawn structure.  This goes into a strategic understanding of any given position.
Iterative Deepening: The applicable idea here might be to consider your list of candidates first, prior to expending to a deeper level of analysis.
Killer Moves: An amazing move discovered in one line of your analysis might be applicable in other lines of analysis... consider it early in the process.
Null Move Pruning: You can better understand your opponents intentions by considering what moves they would make if you were to skip your own turn.
Quiescence Search: When you reach the end of some analysis, make sure everything is still ok if you were to resolve the tension in the position.
MVV-LVA: This one is obvious, but in considering capture patterns, usually a good idea to identify the most valuable victim, and take with the least valuable attacker.
Alpha Beta Search: You can stop considering a line when you find the first refutation to it, rather than continuing to search for a better refutation.


Has anyone attempted to characterize chess mathematically? From years of being student, researcher, and practitioner of chess, I feel like it possesses completeness and elegance that are found in mathematical proofs and theories. Thus, it seems only natural to imagine that it should be possible to describe chess in mathematical terms. By that I mean an elegant description, like a compact set of formulas or a proof that chess belongs to such and such field of mathematics. Intuitively, it feels like it should be able to fit in group theory. Does anyone know what attempts have been made in this regard? I would like to specifically exclude engines, neural networks, and the like from the discussion because, despite the obvious success in increasing the quality of play, those attempts do not constitute theoretical proof.

There are many different aspects of chess which can be formalized mathematically. Since the 19th century at least, chess has been mined as a resource to drive mathematical innovation. So when talking about a mathematical characterization of chess, it's not a single modeling that we are talking about, which grabs every feature, but rather a number of models, in which the power of each is paradoxically in the letting go of some aspect of chess which is not relevant for that analysis.

Perhaps the earliest success (not counting the counting :-) of grains of rice on a chessboard) was Zermelo's Theorem (yes by one of the founders of ZF Set Theory) which states that in chess "either White can force a win, or Black can force a win, or both sides can force at least a draw".

Combinatorial Game Theory (developed by celebrated mathematicians John H. Conway, Elwyn Berlekamp and Richard Guy) has been successfully applied to chess. A couple of assumptions in this theory go against its general applicability to chess though. One is that a win in CGT is solely if your opponent can’t move which does not address stalemate. Secondly there is the notion of “entailing move” (e.g. check) where if one person plays, the other player must respond rather than the first player playing again. But Noam Elkies has derived some non-trivial results in chess endgames by computing their CGT value - references given in his chess page http://www.math.harvard.edu/~elkies/chess.html: "On Numbers and Endgames" and "Higher Nimbers [sic] in Pawn Endgames on Large Chessboards".

You mentioned group theory - well curiously the set of combinatorial games under composition does form an abelian group! To be fair, the two obstacles mentioned above do prevent chess itself from behaving in this way.

There is a massive amount of combinatorial work which has been done around the chessboard. Vaclav Kotesovec has published online an 800 page book just on the subject of non-attacking chess pieces (generalizing the 8 queens problem massively). See http://www.kotesovec.cz/ for the link. This is related to Magic Squares, Experimental Design, etc.

There is also, starting in Finland with Eero Bonsdorff, a long lineage in path enumeration chess problems, counting the number of ways that a position can be reached. This often involves the analysis of Standard Young Tableaux, which also underpin representation theory of symmetric groups. Fibonacci numbers, Catalan numbers and Euler numbers are all frequently found here, together with other combinatorial identities whose realization can be found lurking in ingenious chess compositions. See https://pdb.dieschwalbe.de/search.jsp, and type g='mathematics' in the search box.

The knight's tour problem is also famous for helping to push the study of Hamiltonian graphs, and particularly the challenge of counting the number of such objects. See https://www.mayhematics.com/t/t.htm.

The theory of computation also asks about whether chess is determinate. This is all about arranging sets of pieces in much bigger boards to try to make machines that are equivalent to Turing machines. This brings us to the subject of the limits of computation, which is where I would make the point that if a mathematical theory characterized chess completely, then we should be no more able to reason with it than we are to play at chess itself. That might allow us to escape some of the linguistic challenges of the current laws (e.g. whether pawns can be oriented).

I think there is also research value in a mathematical description of how chess conventions apply consistently to chess problems including fairy chess. Guus Rol has a very ambitious  program which reduces each turn to “micro-phases” and claims to be able to determine with great accuracy how fairy conditions interact in complex “retro-active” situations, where both retro and forward logic is necessary. I don’t know if he will ever complete his theory.

I personally would like to see a more modest theory, which treats each move as atomic and although it doesn’t cover fairy chess so well, at least can cover retro-active aspects of problem conventions such as castling and e.p. Even that has not been done yet.

The mathematical physicist Roger Penrose published a chess position about 2 years ago which was intended to argue his long-held position that there is a fundamentally different kind of reasoning displayed by humans than an AI grounded in "computable functions" can demonstrate. See https://en.chessbase.com/post/a-chess-problem-holds-the-key-to-human-consciousness

Even though the theory of random graphs, and Monte Carlo analysis has been applied very successfully to engines, particularly the most recent generation, I don't think this disqualifies it from being considered a mathematical theory.

There is also a linear algebra approach to counting moves and positions. “If chess is a graph, what is its maximum eigenvalue?” is a very real and interesting question. See Francois Labelle's site at http://wismuth.com/chess/statistics-games.html

Linear algebra can be applied successfully to other chess related questions e.g. how many ways are there for a rook to move from a1 to h8 in exactly n moves? How about a king?

For many years, Noam Elkies & Richard Stanley have been collaborating on a book on chess and mathematics. I don't know when it will finally emerge, or whether they have given up on this. But "The Mathematical Knight" given on Noam's chess page linked earlier perhaps gives a foretaste of that book. Richard Stanley is one of the leading lights in Combinatorics: see http://www-math.mit.edu/~rstan/chess/queue.pdf, and Noam's birthday article https://arxiv.org/pdf/math/0508645.pdf

There is also already a book "Mathematics and Chess" by Miodrag S. Petkovic, but I am not familiar with its contents.

Some of these ideas are listed in a Wikipedia page: https://en.wikipedia.org/wiki/Category:Mathematical_chess_problems, and there's a more specific page https://en.wikipedia.org/wiki/Mathematical_chess_problem.

If anyone else has other examples of chess and mathematics, please mention them in comments and I will try to incorporate them in this response. If anyone has links that illustrate the topics I am mentioning, please add them, thanks.

Finally: math.stackexchange.com has 62 pages of chess entries!?!


NNUE Based Engines - Post Move Analysis Its a bit of a wordy question as there is a lot of background to provide context for thinking and analysis so for that I apologise  you can skip the background if you want but it might provide some additional context that might be useful.
The Background:
Came across an interesting position today which has resulted in me going down a rabbit hole of analysis.
Generally Whites position is looking reasonably strong and is up in material. The d6 pawn is safe from capture because mate would quickly ensue with Rxc8. The black c8 bishop is out of play as long as Black doesn't move his king. The biggest issue is for White at the moment is the knight on g5. It is preventing Blacks king escaping through f7 but otherwise is fairly useless in this position.
The position arises on move 30 with Black playing h6. The knight having no escape squares is going to fall. To make matters worse the knight has no capture possibilities or defence possibilities.
Ultimately I played Ne6 , the pawn took leading to promotion and ultimately Blacks resignation.
I decided to do some analysis on this position and found that the engines really didn't like this position and repeatedly provided the wrong moves unless until they were shown the move.
I could clearly see Ne6 in the lines but for some reason it would suggest Raa8 over Ne6 but the second Ne6 was played it would read that as the better and stronger move.
Question: Why do some engines fail to locate best move options even though it analyses the position and only updates it as the correct move after it has been played? Is this common in NNUE based engines?
Example: Komodo Dragon, Stockfish 12 and Lc0 all saw 2. Raa8 (Scenario B) as a better move than Ne6 (Scenario A) until it moved passed that move and then saw Ne6 as the stronger move
Scenario A
[Date "Nov 2020"]
[White "Yours Truly"]
[Black "Random Hero"]
[Result "1-0"]
[Event "Scenario A"]
[FEN "1Rb3k1/3p2pp/2rP4/4p1N1/4P3/5P1P/6P1/R5K1 w - - 0 30"]

1. h3 h6 2. Ne6! dxe6 3. d7 Kf7 4. dxc8Q Rxc8 5. Rxc8 1-0

Scenario B
[Date "Nov 2020"]
[White "Yours Truly"]
[Black "Random Hero"]
[Event "Scenario B"]
[FEN "1Rb3k1/3p2pp/2rP4/4p1N1/4P3/5P1P/6P1/R5K1 w - - 0 30"]

1. h3 h6 2. Raa8 hxg5 3. Rxc8+ Rxc8 4. Rxc8+ Kf7

This is just an issue every engine has (although they may miss different moves). In this case, it just pruned (ie, didn't consider/didnt consider enough) Ne6. It's not common per se, but has to be kept in mind
Also note Lc0 is not NNUE, it is just a normal neural network not NNUE which is special.


Can I win as black here? In the below position, I'm playing as Black and it's my turn.

[FEN "8/8/1K6/2P5/1P6/8/8/6kq b - - 0 1"]

I've recently gotten back into chess, and this one is driving me crazy. I can't seem to figure a way to win, only draw.  I don't appear to be able to get my king close enough. Can I win as Black? Any ideas would be great!

Yes, it is really an easy win.

The first move is 1...Qe4; 2.Kg4 Kc7, and note that white cannot make any progress without losing one of the pawns, leaving an easy win since your Q can get to g8 after winning the first pawn.

[FEN "qk6/8/8/6P1/5P2/6K1/8/8 b - - 0 1"]

1... Qe4 2. Kg4 Kc7

This is with it going the other way. It is harder, no question, but the first thing is to get the queen in front of the pawns.

 [FEN "8/8/1K6/2P5/1P6/8/8/6kq b - - 0 0"]

 1... Qa8 2. c6 Qb8+ 3. Kc5 Kf2 4. b5 Ke3 5. b6 Qe5+ 6. Kc4 Qa5 7. c7 Qa6+ 8. Kd5 Qb7+ 9. Kd6 Kd4 10. Kd7 Kc5 11. Kd8 Qxb6


How does one apply the Principle of Two Weaknesses into their own game? This sounds like a powerful technique. The problem is that I don't know how to give my opponent two weaknesses when they have none. Any advice?

Ideas I've seen are pushing the rook pawns and weakening the opponent's king or queen side. That's about all I've seen and know in giving weaknesses.

Pushing the rook pawns can be a powerful idea at the right time. But the reason you really need maturity is for big decisions like whether you should do a pawn storm, attack with pieces, or just choose quiet moves to improve and consolidate your position. The "principle of two weaknesses" is just a term for the concept that you shouldn't be so preoccupied with playing for a certain advantage (and perhaps even playing well for it) that you lose sight of a better strategical idea in the position. I like the example of Vladimir Kramnik vs Ernesto Inarkiev. Kramnik played the opening like Kramnik, starting out by isolating and weakening his opponent's queenside pawns, creating the first weakness. He was able to play a timely 16. b4, which made the problem worse, since the black c4 pawn couldn't watch over the b-pawn anymore. After forcing the knight trade on d4, he recaptured with the rook, and after the 24th move white is clearly better. But what I love about this game was Kramnik's move 26. Rg4! You rarely put your rook there. Kramnik was able to realize in the middle of a good position that the best way to finish Inarkiev would be to launch a tactically correct kingside attack, and he finished it off with a nice flourish. Inarkiev was a strong GM, what what sets Kramnik apart was that he was able to change his vision from the queenside to the kingside at a moment's notice.

[FEN ""]
[Event "Petrosian Memorial"]
[Site "Moscow RUS"]
[Date "2014.11.05"]
[EventDate "2014.11.03"]
[Round "2"]
[Result "1-0"]
[White "Vladimir Kramnik"]
[Black "Ernesto Inarkiev"]
[ECO "D53"]
[WhiteElo "2760"]
[BlackElo "2688"]
[PlyCount "79"]

1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. Nc3 Be7 5. Qc2 O-O 6. Bg5 c5
7. dxc5 dxc4 8. e4 Nfd7 9. Bf4 b5 10. cxb6 Nxb6 11. Rd1 Qe8
12. Be2 Na6 13. Ne5 Nb4 14. Qc1 Ba6 15. a3 Nc6 16. b4 Bf6
17. Nf3 Bxc3+ 18. Qxc3 Qc8 19. O-O Bb5 20. Bd6 Rd8 21. e5 h6
22. Nd4 a6 23. Bf3 Nxd4 24. Rxd4 Bc6 25. Be2 Bb5 26. Rg4 Kh8
27. Qg3 Rg8 28. Rh4 Qd8 29. Qf4 Re8 30. Rxh6+ gxh6 31. Qxh6+
Kg8 32. f4 Bc6 33. Bf3 Qc8 34. f5 exf5 35. Qg5+ Kh8 36. Bxc6
Re6 37. Rxf5 Ra7 38. Qh4+ Kg7 39. Rh5 Qg8 40. Be4 1-0


What are some main lines of the Horwitz Defense (d4 e6) besides the French? I'm not the most experienced player by a long shot and appear to be below average, but I know how to play the French Defense quite well and I tried e6 in response to d4 a few times because I don't really know many d4 openings and got a French out of it. How do I respond to c4 or any other common ones (maybe Nf3 or g3?)? I've looked at opening databases and know popular responses, but I want to know why these moves were made. If anyone knows of a video describing it well, that'd be preferable, but I'll gladly take any advice I can get.

Basically, you have a lot of options left to transpose into other openings. I remember having read a book calling this opening the Franco-Indian for this very reason. I do not expect that many White players will actually play 2. e4; they played 1. d4 for a reason and are usually not experts in the French opening.

After 2. c4, you can:

transpose to the Orthodox Queen's Gambit with 2... d5
transpose to the Dutch opening with 2... f5 (but you lose the ability to play the Leningrad system)
transpose to the Nimzo-/Queen's Indian with 2... Nf6
transpose to the Benoni with 2... c5 (thanks @user1583209)
2... Bb4+ is about the only independent line.

2. Nf3 (and to a lesser extent, 2. g3) offer similar transpositional options.


How to distinct a strategical move from a tactical move? I am new here, and I am doing research for academic purposes. I am looking for examples of positions where I can distinguish a strategic move from a tactical move.

Can somebody give me examples of positions and next moves where the next move is

a) a strategic move

b) a tactical move

The difference between a tactical or a strategic/positional move lies in its justification. Almost all good moves have a positional and a tactical justification, otherwise they may be tactical or positional mistakes. The exception, of course, are moves that lead to mate or a big material advantage, those could probably be called purely tactical moves.

Which justification is more important to you depends on your abilities and your style. If the tactical justification of a move is obvious to you, it might seem like a purely positional move. On the other hand if a move has a deep strategic idea, but requires complicated calculation, you may regard it as a tactical move. I'll give you an example:

[Title "White to move"]
[StartFlipped "0"]
[fen "rnb1kb1r/pp3ppp/2p1q3/4P2n/4Np2/5N2/PPP1Q1PP/R1B1KB1R w KQkq - 1 10"]

1.g4 Qxg4 2.Rg1 Qe6 3.Rg5 g6 4.Rxh5

g4 may strike you as a very tactical move: It is a pawn sacrifice and its justification involves a lot of calculation including an exchange sacrifice. But the final goal is really very strategic: Conquering the dark squares, especially f6 and f4. White is winning.

Incidentally this is the big difference between computer chess and human chess: For a computer every move is a tactical move. Every move is justified by the calculation of variations. For humans this is a gradual thing and if you are looking for purely tactical moves you should focus on combinations with a very clear result.

If you want only a crude distinction I would propose to let an engine calculate a few moves: If a move is only viable after a certain search depth, you can call it tactical. Every move viable even at very low ply would be strategic/positional.


Benefits of studying annotated grandmaster games I've started reading about the 1960 Tal vs Botvinnik match and I'm planning on studying many annotated games like these. I was curious about what benefits I can get out of doing this. I've already noticed that I've become more able to read the moves and keep the position in my head. This has strengthened my calculation, but are there any other benefits? Will I start playing more accurately and like the players whose games I study?

Tal vs Botvinnik 1960 is very good as Tal is quite verbose in commentary and what he was thinking about during the game. In addition to the benefits you mentioned, the annotations help you understand what strong players think about in different positions and how they approach the game. Particularly useful is the strong player's positional understanding and ideas in the middlegame. If you happen to play the same openings as those in the annotated games, then you also may get some insights in typical motifs of the opening.


King move to other side During a game of chess, after several moves. Is it an automatic win as soon as you get your king all the way across the board?

I was told this is a tournament rule.

No, this is not a rule in chess. There are plenty of games where one king reaches its 8th rank, and the game continues, with all three results still possible. Here are the Fide rules


How much stronger is a team of GMs compared to a single GM? For example Carlsen is currently the world number 1 and favourite to win a match against any other player in the world. Is he also favoured to win a match against Caruana + Mamedyarov + Ding Liren acting in consultation? How much stronger would a team of top GMs be compared to a single GM?

If it matters: standard classical time controls (shorter time controls makes it hard to consult teammates after all), the team of GMs are side-by-side, and they're playing electronically with the opponent in another room (so opponent cannot eavesdrop on their conversation). The team know each other and prepare in advance, and so does their opponent.

I think a team of GMs are not significantly stronger than a single GM.

My reasoning is: Thinking is fast while communicating is slow and error-prone. It takes dramatically more time to explain an assessment to another GM and while trying to explain some things will be omitted/forgetted. In the end a team of GMs will spend considerably more time to produce a quality move and that move may not be significantly better to justify spending extra time.

Plus, more teammates the team have, there will be more communication channels (grows quadratically respect to number of teammates) and this will make communication less and less efficient.

An alternative approach to overcome inefficiencies:  Let the team to be formed as 1 player (the best player) and N advisors advising player when they believe they can significantly improve players move, otherwise they don't interrupt. Ideally advisors should excel the best player in a particular area of chess. For example Adviser 1 is the best endgame player and advisor 2 is Sicilian expert and so on.

Also the team can switch player in the middle of the game to avoid player to get tired and play weaker especially in long games.


Chess tactics training software Is there a software/app/website to train chess tactics (forking, pins, deflections, decoys, overloading)?

Please help!

Best software I've ever seen for this purpose: CT-Art from Convekta. It's amazing. It's based on Blokh's tactical manuals, gives you positions to solve, and hints when you fail to solve them. And it's cheap (I've seen it new for $20 or so).

Best. Tactics. Software. Evar.


Software with support for Database with opening analysis I'm looking for a software tool that will:

Engine Support. For analysis suggestions.

Support for software evaluation of the moves. I guess this is optional, although I've seen this feature in popular websites where they give a weight on each move. +1.5, -.8, etc, but what is needed is at least give an arbitrary/subjective weight/evaluation on them with a comment as a justification (just an Idea) as comparison.

Organize the moves variations (from the Opening) with trees. The only tool that I've seen that has this feature is chessmaster series, other tools have a similar approach but not with trees but a list of the next "registered" variations/moves, this will be acceptable as well, although a tree will be definitely optimal

Rearrange variations on the tree by weight. Optional. Also seen on chessmaster but in chessmaster it is shown as a 3 star rating on the move so if the moves/variations have weights on them, those can be used to list them in order under the tree.

Support for opening books and easy way to expand them. I want to be able to add a fairly complete Opening book like "olympiad.abk" and expand it, with new options in the openings and add comments on the different variations.

I've analyzed several tools like the ones I mentioned and chess.com, arena, lichess.org and seeing some others, and I can see that these features exist but I'm thinking that no one has them all.

Do you know any tool that has all these features? Or can you think of something even remotely similar?

I found a software that complies with the specifications, at least most of them, it is pretty good and personally I really liked it, its name is CHESS POSITION TRAINER and is a paid software. Thank you everybody.


Did Stockfish blunder a drawn position against Leela here? I don't see how you can defend both pawns at once if the bishop is located on the f8 square. Where did Stockfish go wrong in this game?
[FEN "5B2/3k4/2p4p/4n1r1/8/2R5/6K1/8 w - - 0 1"]

Welcome!
I am not 100% sure of what your are asking.
Are you saying that Stockfish missed a draw by playing Bf8 as shown in the diagram ie there was some other move that could have drawn?
Or are you saying Stockfish missed a drawing line later.
Or are you asking in general where Stockfish went wrong in the game?
If you look at the evaluations then Stockfish seemed to assess itself as losing many moves earlier.
Leela on the other hand thought her position better for quite some time but not necessarily a forced win.
In the lead up to your diagrammed position Stockfish I think is lost and has been for quite a long while.
The Black pawns are wide apart making the defensive Bishop's task very hard. The White K has to keep an eye on one of the pawns whilst the White Rook keeps an eye on the other pawn whilst at the same time trying to harrass and keep out the Black K with checks.
Black has to manoevre carefully but will always be able to shepherd the c Pawn down to the queening square.
I think Stockfish made a strategic error with 40. Ng2 allowing Leela to swap her bad Bishop and get a position with the "Petrosian Knight" verses Stockfish's bad Bishop.
After this swap Leela's Q invaded, Stockfish's position deteriorated leaving a difficult defensive task.
Apologies if I have missed your point.


List of bad gambits? There are many good gambits, from tactical ones such as the Fried Liver Attack, the Evans Gambit, or the King's Gambit, to positional ones such as the Volga Gambit. But there are many bad gambits, such as The Omega Gambit(1.d4 Nf6 2.e4?) or gambits with one trap in mind, and nothing else (Blackburne-Shilling Gambit). Are there more of such gambits?

latvian, halloween, wing, englund, elephant, freds, colorado, danish gambit, tennison, and budapest gambit of the top of my head. These gambits are unsound and a proper response will have the gambiter in a worse position.
Some gambits I do like are kings gambit, smith morra, evans, queens, scotch, benko, lisitsin, staunton, fried liver(Na5), froms.


Deep Fritz 14, Show Plans-How to activate? Does anyone who uses Deep Fritz 14 know how to activate "Visualize Search," aka "Show Plans"? I went to File, Options, and Engine. "Show Plans" is one of the options, but it won't let me activate it. How do you activate it?

It appears to be for future use: Although it is two versions later, to quote the Fritz 16 online manual: "Show Plans - Displays the planned Manoeuver of the engine. The function is not supported by any engine!"

Fritz 16 Manual


in Sinquefield Cup how is white player determined? Do they flip a coin to determine white player? Does the person in that round who has higher points choose? Do they rotate (and if so, how is the first round white player determined)?

In round-robin tournaments, the schedule is known in advance. A very common schedule for 10 players starts with the following games in the first rounds:

Round 1: 1-10 2-9 3-8 4-7 5-6
Round 2: 10-6 7-5 8-4 9-3 1-2

(see this Wikipedia article for more details)

Which player corresponds with which pairing number is determined before the tournament. Traditionally, this is just some kind of lottery, where each player is assigned a random number. It seems this was also the case for Sinquefield 2015:

  Pairing numbers will be drawn randomly at the Sinquefield Cup

For another Grand Chess Tour tournament, Norway Chess 2015, they had a blitz tournament the day before. The winner of that tournament could pick a number first. Because with an even number of players, you play an odd number of games,  the winner could pick a number, say 1, that would give him white in 5 games and black in only 4. The runner-up of the blitz tournament could pick next, and so on.


Books that help improve your chess without a chessboard? I am looking for books that can help me improve without a physical/digital chessboard. I have a kindle, and I have many places in school where I can read, but not many where I can open a chessboard without people coming from all 4 corners to see what I am doing.

EDIT:

To help for further reference, I am 1750 in Correspondence chess in chess.com

One book that can mostly be read without a chess board is Willy Hendriks' "Move First Think Later", one of my favourite chess books. It mostly contains puzzles and some interesting musings from the author.

Also, even though you are not looking for a digital solution, I have to add that I find DroidFish (available on Android) to be a nice compact way to read chess books on my daily commute while still having the power of a GM level analyst right there.


What does a team captain in chess do? I was made the "team captain" of the chess club I am a member of for a match with a chess club in a different city.I want to know all the requirements for being a team captain.All I did was choose the team members based on the highest rating.

Let's see what FIDE says, Team Captain’s Role in Team Tournaments:

  (a) The role of a team captain is basically an administrative one
  during play. Depending on the regulations of the specific competition,
  the captain shall be required to deliver at a specific time a written
  list naming the players in his team participating in each round, to
  communicate to his players their pairing, to sign the protocol
  indicating the results in the match at the end of the play, etc.

  (b) Whenever the team captain speaks to one of his players, he should
  do so only through or in the presence of an arbiter, using a language
  the arbiter can understand.

  (c) A captain is entitled to advise the players of his team to make or
  accept an offer of a draw or to resign a game, unless the regulations
  of the event stipulate otherwise. He must confine himself only to
  brief information, based solely on the circumstances pertaining to the
  match. He may say to a player, “offer a draw”, “accept the draw”, or
  “resign the game”. For example, if asked by a player whether he should
  accept an offer of a draw, the captain should answer “yes”, “no”, or
  delegate the decision to the player himself. He shall give no
  information to a player concerning the position on the chess board
  and/or the clock times, nor consult any other person and/or computer
  as to the state of the game. The captain shall refrain from any
  intervention during play.

  (d) Players are subject to the same prohibitions. Even though in a
  team competition there is a certain team loyalty, which goes beyond a
  player’s individual game, a game of chess is basically a contest
  between two players. Therefore a player must have the final say over
  the conduct of his own game. Although the advice of the captain should
  weigh heavily with the player, the player is not absolutely compelled
  to accept that advice. Likewise, the captain cannot act on behalf of a
  player and his game without the knowledge and consent of the player.

  (e) A team captain should encourage his team always to follow both the
  letter and the spirit of Article 12 of the FIDE Laws of Chess
  concerning the conduct of the players. Team championships, in
  particular, should be conducted in the spirit of the highest
  sportsmanship.

A player which has highest rating and better knowledge about rules is the best candidate to be a captain.


Sacrifice a pawn to reorder the pieces Consider a chess variant which plays exactly (*) as chess except that the players have a special option for first move.

White can, instead of moving a pawn/knight as its first move, sacrifice any of its pawns (removing it from the board) to reorder its pieces (within the first rank).

Then, Black has almost the same option: it can reorder the pieces instead of moving a pawn/knight, but a sacrifice of a pawn is optional.

Would it be advantageous for White/Black to pursue this option instead of a regular opening move?

Which would be the best options for sacrificed pawn and permutations of pieces?

(*) For castling: if the king is between the rooks, castling follows the rules of Chess960/Fischer Random Chess. If it isn't, castling is forbidden.

A few thoughts, but as I expressed in the comment, I don't think this question will have a single good answer.

Based on general opening principles in regular chess, I would not sacrifice a central pawn, because that might reduce control on the center.

Secondly, in order to speed up development, I would sacrifice a pawn that already opens lines or diagonals for the development of rooks/bishop/queen.

Based on my experience playing Fischer random/chess960, I found positions quite convenient where the bishops are on a1, b1, g1 or h1, so that they immediately attack something once the pawns moved away.

Combining all this, one possible position could be

8/8/8/8/8/8/PPPPPPP1/BBKRQNNR w - - 1 1

Here I go for an atack on h7, g7, and also all pieces could support any operations in the center of the board.


Ways to improve defensive skills Last night I played two OTB games with a friend of mine and in both games I reached decent, even winning positions. At some moment though I overlooked my king safety and blundered horribly, which lead to losing both games.

Going back further it occurred to me that I do this almost on a regular basis! I reviewed few games in which I had a great position and then I made a bad move which lead to either the position being equal or even being worse. In these games the problem was not the king safety in particular, but some other positional or tactical error.

I've identified the problem as being too focused on attacking, trying to checkmate my opponent, then I relax a bit too much, thinking I'm winning, and make a bad move. Obviously, I need to work on avoiding blunders and improving my OTB analytical skills, but in this question I would like to focus on improving purely defensive skills, especially when under pressure.

One very important aspect of defense, as defined as Nimzowitsch, is the term of prophylaxis. The thing is that I'm not certain when I should make a prophylactic move that doesn't throw my advantage away as well.

One way for improvement in finding prophylactic moves would be studying the games of world class players, famous for their defensive skills and strong positional understanding. The name of Tigran Petrosian immediately comes to mind, but where would I be able to find some of his annotated games so I can really understand and appreciate the strength of his moves?

What other players would you recommend to study in order to improve in this particular area?

Maybe the most crucial question would be the following:

How to deal with the psychological pressure of having a great position and having it collapse over the next few moves?

What other ways for improvement would you recommend?

"...where would I be able to find some of his annotated games so I can really understand and appreciate the strength of his moves?"

Although you can find annotated games of Petrosian all over YouTube and some chess-related websites, I would recommend purchasing these books if you are interested in his style.

What other players would you recommend to study in order to improve in this particular area?

Karpov, Korchnoi, Ulf Andersson, Kramnik, Carlsen, Fischer.

How to deal with the psychological pressure of having a great position and having it collapse over the next few moves?

From personal experience, during the game just train yourself to not get too excited during the attack and before making the next attacking move spend time analysing how much of your defence get's hindered and how critical can that be in the long run. If the position is already collapsing, then either continue attacking if you are fully sure you will be able to checkmate faster than your opponent, or come back to defend and hope for a blunder or draw. After the game, analyse the game, just as you did.

What other ways for improvement would you recommend?

I would recommend playing as much games against higher rated opponents as possible. Thats the way I personally improve.


EXTENDED New Year's Math Riddle: 5-fold repetition & 75-move rules This puzzle extends Rewan Demontay's New Year Math Riddle.
Rewan asked (essentially): if the players co-operate, what's the largest number of times a given diagram can occur in a game before reaching the point when someone can claim a draw? In order to group everything together, I'll re-state that question as Q1 here:

Q1: Under the 3-fold repetition & 50-move rules, how many times can a diagram occur? Call a diagram which achieves this 3-critical.

Q2: Under the 5-fold repetition & 75-move rules, how many times can a diagram occur? Call a diagram which achieves this 5-critical.

Now let's make some actual chess games:

Q3: Find a 3-critical diagram that is a unique shortest proof game to its first occurrence.

Q4: Find a 5-critical diagram that is a unique shortest proof game to its first occurrence.

Answers to all 4 questions

Q1: Under the 3-fold repetition & 50-move rules, how many times can a diagram occur?

A1: Even if it were mandatory, the 50-move rule has no impact: the answer is still 22 as per Rewan's post:
   2 (occurrences without triggering the draw)
 x 2 (White or Black to move)
 x 5 (number of castling rights intact: 4->3->2->1->0)
= 20
 + 1 (en passant)
 + 1 (the final 3rd occurrence)
= 22 times

There are 21 transitions between the 22 occurrences, each taking at least 2.0 moves which gives 42.0 moves. Also we must flip sometimes between White & Black having the move, which takes an extra 0.5 of a move each time to triangulate. If White were to move in the first, the player to move in each of the 22 critical positions is:
W-WWBB-BBWW-WWBB-BBWW-WWBB-B

Five 0.5 flips give a total of 42.0 + 5 * 0.5 = 44.5 moves.
Note that we require a diagram where parity can be switched by a free bishop or queen, as knights can't triangulate, and kings & rooks are tied up with castling rights. Rewan's diagram is sufficient for this, in order to achieve the 44.5, and in fact we still have a little slack and could waste another 5.0 moves. Because of e.p., the move prior to the first occurrence of the diagram was a pawn move, which zeroed the 50-move clock. For definiteness, let's say that the maximum is 49.5, to avoid draw by repetition and 50-move rule on the same move.

Q2: Under the 5-fold repetition & 50-move rules, how many times can a diagram occur?

A2: One might think that the answer is 42:
   4 (occurrences without triggering the draw)
 x 2 (White or Black to move)
 x 5 (number of castling rights intact: 4-3-2-1-0)
= 40
 + 1 (en passant)
 + 1 (the final 5th occurrence)
= 42 times

But in fact the diagram can only occur 37 times now, not 42.
There are 41 transitions between the 42 critical positions. Each takes at least 2.0 moves, which takes 82.0 moves, together again with the 2.5 moves for parity switching so that the player to move in each of the 42 critical positions is:
W-WWWWBBBB-BBBBWWWW-WWWWBBBB-BBBBWWWW-WWWWBBBB-B

84.5 moves would be needed, but the game will end at 75.0. So how many occurrences of the diagram can we get before we bring the game to a close by 5-fold repetition, before the 75-move rule ends us? If our budget is 74.5 (or even 75.0) moves, so we must eliminate 5 recurrences.
It takes us 74.0 moves to reach the diagram for the 37th time. By skipping the en passant threat at the beginning, we can reach the position more quickly.
BBBB-BBBBWWWW-WWWWBBBB-BBBBWWWW-WWWWBBBB-B

Q3: Find a 3-critical diagram that is a unique shortest proof game to its first occurrence.

A3: PG in 3.5. The last move to reach this position for the first time is a pawn move, as we then launch into the full 44.5 move sequence.
[FEN "r1bqkbnr/pppp1ppp/n7/8/4pP2/8/1PPPP1PP/RNBQKBNR w KQkq - 0 1"]

Q4: Find a 5-critical diagram that is a unique shortest proof game to its first occurrence.

A4: Proof game in 2.5 moves to a diagram which can occur 37 times.
[FEN "rnbqkbnr/1ppp1ppp/B3p3/p7/8/4P3/PPPPNPPP/RNBQK2R w KQkq - 0 1"]

This will take us 84.5 - 10.5 = 74.0 moves, which is perfect because White's 3rd move to reach the diagram for the 3rd time is not a pawn move or capture. So the game does not end prematurely by conflated draws by 5-fold repetition & 75-move rule.


Chess players who committed murder Apart from Raymond Weinstein, are there any other examples of chess players of at least Master strength who committed murder?

Claude Bloodgood, the popularizer of the Grob (1. g4), must be far and away the most famous. At one stage his USCF rating was second only to Gata Kamsky! It doesn't get much worse than murdering your own mother.


How can I to hold on to the pawn plus for black in the Queen's Gambit Accepted? A few years back I used to play with a player who always accepted the queens gambit pawn and used to hold on to it and sometimes win with the pawn plus.
Is there any specific variation that can be studied in favour of black in queen's gambit accepted?

Black can sometimes hold on to the Pawn if that is the goal.  Black has to play an early a6 and b5.  One possible variation is:

[FEN ""]
1. d4 d5 2. c4 dxc4 3. Nf3 a6 4. e3 b5

Although Black will hold on to the extra C-Pawn, White can counterattack with a4, b3, and Nc3.  Black has neglected development, and according to MegaBase 2012, White scores 60.6% from the diagrammed position with the move 5. a4.


What's the correct way to calculate centipawn loss? I've been letting the engine analyze a position at depth D, then making the player's move and letting the engine analyze the resulting position at the same depth D, and then taking the difference between the first score and the second score (both from the same player's perspective, of course). This procedure has the property that it's possible to have a negative centipawn loss: it will be negative if the engine prefers the player's move to its initial choice after seeing one ply farther in the line beginning with the player's move. Is this expected and acceptable? The alternative would be to have the engine analyze the position after the player's move at depth D - 1, which would guarantee a non-negative centipawn loss.

No. Your assumption is based on searching everything up to depth D, but no modern chess engine would do that. It's complicated to explain, but fair to assume only some subtrees up to depth D are explored. The other trees got "cut" off for various reasons, most likely they are not good.

Chess programming is all about skipping the search tree accurately. The conditions could depend on the depth to the root, previously visited nodes, and many others. As you make a move on the board, all parameters change, even the cache for keeping the transposition table change. Trees that are previously visited may now be skipped, and vice versa. The change of information in the transposition table could have a significant impact in the new search path.

  it will be negative if the engine prefers the player's move to its initial choice after seeing one ply farther in the line beginning with the player's move. Is this expected and acceptable?

Anything can happen. The difference can be positive, negative, or remain unchanged.


What is the status for seven man end game table bases? There are complete (or nearly complete) six man end game table bases available for download, and even online.

What is the status of seven man table bases? Is there still active development in this area? How much progress has been made? Is there any estimated time for when it will be completed, or at least complete enough to cover all the common seven man positions that occur in real games?

Seven man end game table bases are already available online:

http://chessok.com/?p=28049

By the end of 2013 they should be available off line as well. The size is 140 000 gigabytes so there is an obvious problem with copying them. They did not compute 6 white pieces versus 1 king since they decided it was pointless.

Interesting fact- the longest forced checkmate is 549 moves!


An important and interesting Bishop endgame In a 1993 game played by Wojtkiewitz vs Khalifman, the following endgame appeared on the board. Black to move.
[FEN "5k2/1p4p1/1p2bp1p/3p4/5PP1/P3P2P/1P1K2B1/8 b - - 0 1"]

Stockfish gives +0.9 for white.
Is the position a win for White or a draw?

I have seen this position in Dvoretsky's endgame manual. According to his analysis, white is winning after Ke7, Kc3 Kd6, a4!, eventually getting the pawns to b5 and f5, king to d4 and breaking through with e4 at the right moment.
Update. Actually, I have checked it, and in the book the position is already after Ke7, Kc3 Kd6. Here white has to play a4 to stop b5. Importantly, earlier b5 does not work for black either, because white has Kc3-b4 winning the b5 pawn.
Update 2.
As @Evargalo correctly pointed out, the key to this position is the pawn ending arising after 1. ... Ke7 2. Kc3 Kd6 3. a4 g5 4. Kd4 Bf7 5. Bf3 Be6 6. f5 Bf7 7. b4 Be8 8. b5 Bf7 9. Bd1 Be8 10. Bb3 Bf7 11. e4 bg8 12. Ba2 Bf7 (probably a time-winning pass) 13. Bxd5 Bxd5 14. exd5 Kc7.
[FEN "8/1pk5/1p3p1p/1P1P1Pp1/P2K2P1/7P/8/8 w - - 0 1"]

Here the game continued: 15. Kc3 (aiming at Kb4 and a5 to enable Kc5 and d6) Kd6 16. Kc4 (triangulation). Now:
(1) 16. ... Ke5 17. a5 bxa5 18. Kc5 a4 19. d6 b6+ 20. Kc6 a3 21. d7 a2 22. d8Q a1Q 23. Qd6+ Ke4 24. Kxb6 and apparently white is winning thanks to the b-pawn. White gets his queen to c6, king to c8 and push the pawn. Black resigned after 10 more moves;
(2) 16. ... Kd7 17. Kb4 Kd6 18. a5 Kxd5 19. a6 bxa6 20. bxa6 Kc6 21. Ka4 b5+ 22. Ka5;
(3) 16. ... Kd7 17. Kb4 Kd6 18. a5 bxa5+ 19. Kxa5 Kxd5 20. Kb6 Kc4 21. Kxb7 Kxb5 22. Kc7 and the pawn endgame is winning.
Actually, at first I thought it is an example of impressive calculation from the white player, but then maybe, it all can be found by elimination. You see that getting your pawn to b5 is your best bet to win the bishop endgame, then you have to go to the pawn endgame because otherwise it is a fortress, and then it is a draw unless you go for the queen endgame where the b-pawn is your only chance. So maybe it is an example of how avoid unnecessary calculations.


Caro-Kann advance variation w/ 3. c5 dxc5 I like to play the Caro-Kann as black, and in response to the advance variation play 3... c5!? This works really well for me (~1800 USCF), but as I've gotten better I'm being forced to deal with the response which is common at higher levels, which is 4. dxc5! Nc6 leading to a position which I've found uniquely uncomfortable (and after only 4 moves!):

[FEN "r1bqkbnr/pp2pppp/2n5/2PpP3/8/8/PPP2PPP/RNBQKBNR w KQkq - 1 5"]

Although the computer thinks Black is okay (stockfish depth 29: +0.5) this opening feels very different from other variations of the Caro-Kann and as such I've felt recently that I should study the variation in more detail, but I've really struggled to become more comfortable in this position despite putting more time into this position than almost any other in my repertoire. Here are the reasons that I can see why I'm having trouble:

Fundamentally, black is cramped and down a pawn. Worse, in many variations persist for a long time even with perfect play. Proving compensation seems very hard.
There are a bazilion ways white can play which keep this cramping theme - at almost every move there are 5 moves within a half evaluation point of each other, and my opponents tend to break from the "main lines" that I can see in opening explorers very quickly. Memorizing moves & responses feels fairly futile past a couple moves, and these lines usually don't lead to what I'd call a "comfortable" position.
If I'm not very careful, White's queen-side majority can create passed pawns and with such a cramped position, this can prove deadly. I've lost several games in this fashion.
I've struggled to find much theory or discussion of this position since 3... c5 is it's a 10-to-1 side-line of the main Caro-Kann (although I'm probably just not looking in the right places). The couple books I've looked at don't cover 3... c5.

So, I'm looking for some advice from more experienced players. How can I study / improve this opening? Am I thinking about something wrong here? Is this just a fundamentally uncomfortable position (and probably the reason 3... c5 isn't the main line) and I should just accept that and play a different opening if it's too much? Should I just bunker down and spend a lot of time memorizing lines to guide myself through the opening stages here? I've struggled to gain much insight by looking at pro games (and this is played occasionally at the highest level), but maybe I should try harder at a that?

OK, after reading your reply to my question above, I can more accurately answer.

First, contrary to Fuxia's comment, the move you played, 4...Nc6, is actually more popular now at higher levels than Botvinnik's 4...e6. To quote GM John Shaw's 2016 book:

  4...Nc6 is more popular these days and can be viewed as slightly more ambitious, as well as somewhat riskier. It can lead to exceptionally
  sharp play....

Thus, based on your answer above, I would not play 4...Nc6 since it simply does not suit your style. If you are going to play 3...c5, then I would play 4...e6 as it leads to more positional lines, that are easier to understand. Also, not that you are old, but if you are having problems with blundering, going into sharp lines with 4...Nc6 may be suicide.

Here is what I would recommend:

  [FEN ""]

  1. e4 c6 2. d4 d5 3. e5 c5 4. dxc5 e6 5. Nf3 (5. Be3 Nh6! {This is actually very positional since if white takes, most of the lines favor the black bishops.}) (5. a3!? {Shaw}) Bxc5 6. Bd3 Nc6 7. O-O Nge7 {with the idea Ng6, Qc7, and maybe f6 after O-O. Also, instead of Qc7, you can also play Bb6-c7 with the same type of pressure on e5.}

Now, in any case, that is barely touching the surface. If you want to play that line, you will need to look at more specific material. Here are some study materials.

"Opening Repertoire: The Caro-Kann" by IM Jovanka Houska (chapters 9-11)
"Playing 1.e4: Caro-Kann, 1...e5 & Minor Lines" by GM John Shaw (chapter 2).
"Practical Black Repertoire with d5, c6. Volume 2 The Caro-Kann and Other Defences" by GM Alexei Kornev (chapter 6+7)

All three books have advantages, and all are pretty new, having been published in 2015, 2016, and 2017 respectively.


What are openings which were once thought good, but are now shown to be inferior? Are there any openings that were once often played, but are now known to be very bad moves?

Openings tend to go in and out of fashion. At example, the Berlin wall was considered to be very dull and unambitious, but then Kramnik played it against Kasparov to become World Champion. Nowadays the Berlin wall is a regular guest at top tournaments. The same can be said about the Scotch Game, which was rarely seen at the highest tournaments until Kasparov picked it up.

So most of the time when openings are not often seen it is because of fashion. One more important reason is that there may be critical lines that lead to unfavourable situations (like that the opponent can force a draw by repetition). Usually it takes a few years, but then someone comes up with a different idea and the lines are playable again. I remember vaguely a game in the poison pawn variation of the Grunfeld Indian between top 10 players (can't remember who, sorry) that turned the evaluation of the whole line upside down. Such games can kill or revive a line all of a sudden.

More generally, in my opinion there are several phases of the way chess is played. In the early days attack was everything and theory was not well developed, so gambits of all kinds were played (Evans Gambit, King's Gambit,...). I'd call it the romantic phase. Then the scientific phase began with lots of general rules discovered and well researched plans. This led to different opening, more balanced systems becoming the mainstay of tournament play. If you followed the rules of thumb your opening were considered sound. Nowadays we have entered the computerized phase, where concrete variations checked by computers rule the tournament halls. This led to the rise of some very sharp, concrete opening systems that otherwise no-one would have dared to play. So, depending on the time in history your question is asked, you will get a different answer about which opening is a bad choice.


In correspondence games, is it considered cheating to get an engine evaluation of the current position? Is it considered cheating to simply get an engine score for the current position in an ongoing game without looking at any of the generated lines? I'm guessing the answer is yes, but just curious (and yes, I'll admit to doing this before in casual games!).

From Wikipedia's article on Correspondence Chess: "However, the influence of computer assistance remains controversial in both official and casual play, and consensus on the issue of whether to allow computer aid is still lacking" It depends on the organization. Although I think looking at just the evaluation is fine, there is no definite rule on engine use, as in correspondence it can be extremely hard to detect who's using an engine when the players are given so much time to analyze their games. In casual games between your friends it should be perfectly fine, but on a website or through an organization, you should ask them.


Automatic draw rules In developing a computer chess program, would it be reasonable to automatically declare a draw match for these two scenarios:

A.  Player 1 has a king and a knight, player 2 has only a king left.

B.  Player 1 has a king and a bishop, player 2 has only a king left.

Yes, since it is not possible to produce a checkmate in these circumstances.
See also the FIDE rules:

1.3 If the position is such that neither player can possibly checkmate the opponent’s king, the game is drawn (see Article 5.2 b).
5.2 b The game is drawn when a position has arisen in which neither player can checkmate the opponent’s king with any series of legal moves. The game is said to end in a ‘dead position’. This immediately ends the game, provided that the move producing the position was in accordance with Article 3 and Articles 4.2 – 4.7.


Strategy behind this chess position? I am only used to check-in-n type of puzzle, so I am quite lost when my friend challenge me to this endgame position. EDIT: figured out how to do the chess board (note: the board seemed to be flipped, the black pawn should be close to queening)

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Can Black win?
Black move first.

[fen "8/7Q/7K/8/8/kp6/qp6/8 b - - 0 1"]

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It seemed very obviously that black should win, with an advantage of 2 nearly queening pawns. Yet the way the question is asked make me think otherwise.

According to the Nalimov Endgame Tablebase: http://www.k4it.de/?topic=egtb&lang=en this position is a win in 40 moves for black, if black promotes for a knight to block the upcoming avalanche of checks.
However if black promotes for a queen it's a draw.