Is Deep Blue outdated? I bought a laptop, a Dell, model XPS 13. I found a technical review which mentioned the Fritz test:

Fritz is a chess benchmark that tests the computing capabilities of the CPU with various chess moves. The Intel Core i7-8550U managed to get 10.675 million moves per second. For comparison, one of the most powerful computers, Deep(er) Blue, was able to squeeze out 200 million moves per second. In 1997 Deep(er) Blue even beat the famous Garry Kasparov with 3.5 to 2.5.

But then I found this link that claims that even an iPhone 5s would be almost better than Deep Blue.

I am now confused, are Deep Blue and Deeper Blue different? Are algorithms more efficient today?

IBM claimed the machine could search for 200 million moves per second, while Stockfish in the recent AlphaZero match could "only" search for 80 million per seconds on a modern multi-core machines. But... it was unclear how exactly IBM derived the number. There's no universe definition on how an engine calculates number of moves per second. How it's done is implementation dependent. It's not always possible to compare engines by number of moves searched per seconds. There was a somewhat related discussion on Rybka:

  http://talkchess.com/forum/viewtopic.php?t=30992&start=0&postdays=0&postorder=asc&highlight=report+engine+speed

Deep Blue is out-dated, it was made before this century. Please note I was too young for the project, so my understanding might not be 100% correct.

Deep Blue had a paper. I just had a quick 10 minutes look. Let's give a try:

2018, nobody uses human grandmaster games for tuning
Deep Blue didn't focus  on deep search as much as modern engines like Stockfish (https://en.wikipedia.org/wiki/Deep_Blue_(chess_computer)#Aftermath supports my argument)
Deep Blue was running on a dedicated machine. We don't do that in 2018.
IBM had 32GB hash table, we can do better than that in 2018
Deep Blue didn't have something known as null move pruning. (page 5 in the paper). I'm very confident all modern engines use it. It's a simple technique.
Deep Blue didn't use late move pruning (I failed to see in the paper)
Deep Blue used MPI for parallel search. This doesn’t happen anymore.
Deep Blue was running evaluation on hardware, make no sense in 2018. If Stockfish did that, you wouldn't be able to use the engine on an iPhone.
Deep Blue had very basic move ordering (http://www.talkchess.com/forum/viewtopic.php?t=64021&postdays=0&postorder=asc&topic_view=flat&start=10 by Alvaro Cardoso supports my argument)
Deep Blue had a 5-piece tablebase. Stockfish has 6.
Deep Blue pruned less than modern engines.
The algorithms was hardware specific (e.g. generating moves). We don't do that anymore in 2018. We have efficient 64 bits operations.


Are there statistics on the frequency of tactical motifs? I was taking a look at the tactical motifs on chess tempo and I was curious to know which motifs are encountered most often and which motifs are encountered the least?  Are their statistics for this?

I'm going to suppose that compiling this sort of data would be nearly impossible because the question is, while it seems very specific, is actually far too broad. As a database developer I face these kinds of scenarios very often. One of my special favorites is just the idea of a date and time. It seems so simple but the second you start to really look at it you see it is in fact very deep and has many facets.

Let's start breaking this apart.
1. We assume you mean in Grand Master level games only.
2. Do you consider only tactical motifs that actually occur in the game or do you consider positions that are directly threatened? These positions would actually be highly important for study because even though they do not occur in the actual game, both players needed to consider them.
3. If you consider positions that do not actually occur over the board, how deep in the analysis do you go?
4. Do you consider tactical motifs that are standard operations like a simple pin or do you only consider tactical motifs used in a combination?
5. Do you consider tactical motifs that occur in any combination or only those that actually work?
6. If you only consider those in combinations that work, what do you mean by "work"?

You see where I am going with this. There are so many things that need to be considered before the data can actually be transformed into something informative that it becomes impractical. This should not really be surprising for a topic that chess players through the centuries have had a difficult time defining: what is a tactic? What is a combination? Is a combination just a set of forcing moves even if it leaves the position exactly equal? What if it leaves the player who initiated it weaker? It's like the US supreme court justice said. We might not be able to define it, but we "know it when we see it." But that sort of definition doesn't help us transform a mass of data into actual information.


Is online chess learning as effective as using books? I started playing chess long before the Internet or even computers were tools that could help you learn chess. Trainer GM Arthur Yusupov believes that you should set up every position on a board, and study it that way (he even puts this in the forward of most of his books).

Recently, I have been doing tactics on one of the various sites I belong to, and I found that it is way too easy to just move the pieces and guess at the answer compared to when I read a book, and have to really think about what the answer is.

Which is more a effective way of learning and why?

I have found that reading books makes one concentrate more, and the material is usually covered more in-depth. I think that the "in-depth" part of this is what is important. The explanations are usually much better, and geared toward learning something more permanently.

I find that my work on a famous chess site that you buy materials has been much more shallow. I can click, and it does not matter if I get it right since it shows me what I did wrong immediately. Instead, when I read a book, I really have to think hard since a book does not spit out the answer.

I also just found this Quora question, and the level of players answering is astoundingly high, and they all seem to agree that books are still the way to go.


Why is Kf8 the recommended move here? in this position:

[FEN "rnbqk2r/pp2bppp/5n2/1Bpp4/8/3P1N2/PPP1QPPP/RNB1K2R b KQkq - 3 7"]

Stockfish 8 gives the move of Kf8, and claims my move of Bd7 is an inaccuracy. I don't quite understand why. I can see that it breaks the pin on my bishop on e7 and sets up for possible tactics with Qa5, but that's not going to happen against decent opposition and surely I'd rather my right to castle and connected rooks rather than my rook doing nothing on h8 and a somewhat weakened king.

Maybe this is just one of those positions where an engine gives moves too removed from human play to really comprehend?

Any help is appreciated, cheers.

sets up for possible tactics with Qa5, but that's not going to happen against decent opposition

Well, the Qa5+ tactics is exactly what's going to happen, and Black also threatens ...a6, ...b5 and ...c4 trapping the Bishop. It looks like White cannot avoid losing a piece, but he will only get a pawn and some light pressure in return.

[FEN "rnbqk2r/pp2bppp/5n2/1Bpp4/8/3P1N2/PPP1QPPP/RNB1K2R b KQkq - 3 7"]

1... Kf8 2. Ba4 {2. a4 doesn't help because of ...a6, trapping the bishop; 2. Nc3 fails to ...d4 and the bishop will again be unprotected} Qa5 3. Nc3 d4 4. O-O dxc3 5. Re1 Qd8 6. bxc3


Carlsen-Caruana Game 12 Any online search about the recent game 12 in Carlsen-Caruana's WCC is filled with the surprise caused by Carlsen offering a draw when in a (possibly?) winning position. It was announced on chess.com that

  the top eight chess engines in the CCC will play a 2x-round-robin tournament starting after move 31 of the world chess championship game 12. The time control is rapid chess, 30 minutes plus five-second increment.

At the moment of writing this, I can see the tournament here. But I don't know enough about chess or at least how chess.com works to understand what's happening.

Is the tournament leading to some consensus on how good/bad Carlsen's decision was?

Is the tournament leading to some consensus on how good/bad Carlsen's decision was?

Not quite. As others have pointed out, Carlsen's decision was based on factors outside that one game. With a stronger position and a large time advantage, Carlsen most likely could have won game 12, but Caruana had just tied Carlsen in 11 consecutive games, several of which had each player blunder away a significant advantage. Caruana showed he could go toe-to-toe with our Norwegian champion, and so attacking his position would not come without risks.

Meanwhile, a draw effectively changed the championship to a 4-game Rapid tournament (then Blitz if that ended in a tie), where Carlsen is a heavy favorite. While Carlsen and Caruana are roughly equal in standard chess (2835 and 2832 respectively), Carlsen is much stronger at Rapid (2880 and 2789) and Blitz (2939 and 2767). Why extend a game in an even format when a draw moves to a format you're stronger in?

Having said that, the Chess community was not happy at all to see that draw offered (source: I was unhappy). I'll concede it was a technically correct decision, but as someone who had been waiting 11 games for a win, seeing one materialize then simply vanish was frustrating. It left a lot of people asking "What would have happened if Carlsen hadn't offered that draw? How would the game have ended?", and that's the question these games are answering.

In other words, the tournament isn't leading to some consensus on how good/bad Carlsen's decision was. It's leading to some consensus on how good/bad Carlsen's position was.

All in all, the tournament showed that Carlsen had a very good position. After 56 games, black finished with 27 wins, white finished with 3 wins, and there were 26 draws. That's a tremendous advantage. Any grandmaster would be ecstatic to hear that, for a chess engine, their position was only losing in 5% of games played.

What's more, this tournament had given both sides equal time. That's not completely accurate, as Carlsen had a significant lead on time (though I've forgotten just how much). That implies these results are even too conservative, and that Carlsen may have had a larger lead.

Having said that, humans and computers play in very different styles. Because it's winning for a computer doesn't guarantee it's winning for Carlsen (though he's practically a computer anyway), but it does show he had a strong opportunity to win it all in game 12.


Good online database, or do I need ChessBase? I just bought a premium account at chessbase.com, including full access to tools like the Live Database. I have to say, I'm a little bit disappointed by the features they provide.

My question is, is there a better online analysis/preparation tool that I can just open anywhere in a browser, or do I need to install the ChessBase program to get more features?

More specifically, this is one feature that I miss in the Live Database:

Find all games for a specific player, as either white or black, and for each position, see which moves they made (and the result of those games).

Basically, the possibility to filter the "Live Book" window on a specific player with a specific color.

I assume this can be done in the ChessBase program, although I have never actually tried the program.

I also wonder, say I go ahead and buy the ChessBase program. Is it still necessary to have the premium chessbase.com account, or is that all included when I buy the program?

Chessbase is by far the best preparation tool - almost all of the top players use it for a reason (as well as most serious players in general).

I wouldn't recommend using the online version though, for a couple of reasons.  As you have found, a few features seem to be missing.  In addition, having wifi access is required if you want to look someone up (which can be inconvenient if you're at a tournament and need to prepare for an opponent quickly).

The ChessBase program is the way to go.  I've been using it for around 10 years now and it's been great.  It's straightforward to look any player up in any database.  The program also supports the top chess engines (like Komodo, Stockfish), and allows you to save your games in databases.

The normal version would be fine.  The more premium versions give access to a few perks, but I think it's overrated.


What is a pure checkmate? Recently I heard something about pure checkmate. This is a special kind of checkmate where each of the squares around the king has to be covered by just one single piece. One simple example of this would be checkmate using two pawns and the king:
[FEN "3k4/2PP4/3K4/8/8/8/8/8 w - - 0 1"]

Unfortunately, I couldn't find any more detailed information about this topic, which is the main reason for this question.
To make the question slightly more specific, I'd like to know what are the exact circumstances for a mate to be considered pure?
Is it allowed to have opponent's pieces involved in the check mate? For example like this:
[FEN "1r1q1r2/4R1p1/2p2pkp/p4Q1N/n2PP3/P5N1/5PPP/4R1K1 w - - 0 1"]

According to Wikipedia:

"A pure mate is a checkmating position in chess in which the mated king
and all vacant squares in its field are attacked only once, and
squares in the king's field occupied by friendly units are not also
attacked by the mating side (unless such a unit is necessarily pinned
to the king to avoid it interposing to block the check or capturing of
mating unit."

Essentially, a pure mate is a position in which each square around the opposing king is attacked only once by the mating side, so your first example is indeed a pure mate. However, your second example is not. While kings can be blocked off by their own units, they cannot be attacked unless they are pinned, which they aren't.
To summarize, the Black king can be surrounded by its pawns and pieces so long as they are not attacked, and if they are, they must be pinned. Furthermore, the pin must prevent the pinned piece from interfering with the mate.
As far as I can tell, multiple pieces may be on the board so long as the stipulations of a pure mate are met. The enemy pieces surrounding the king’s squares can be attacked, so long so as the mating piece is actually capable of mating, i.e. it cannot be captured or blocked.
Wikipedia gives an example from the final position from the famous Evergreen Game (link the chessgames.com).
 [Title "”The Evergreen Game,” Adolf Anderssen-Jean Dufresne. Berlin GER, 1852"]
[FEN "1r3kr1/pbpBBp1p/1b3P2/8/8/2P2q2/P4PPP/3R2K1 b - - 0 1"]

In this position, each of the Black king's available squares that it could move to are attacked exactly once by the White pieces, and the black blocking pieces are not attacked by white pieces at all. Although the White pawn that blocks off the g7 square for the black king is attacked, this is a real pure mate from high-level play nonetheless.
If you wish to see a constructed position for a pure mate, @DM has a great position in his answer to a related question on this site.


Could Karpov defend against Kasparov in 1990 championship? I have watched this video, where Kasparov explains the variations after his knight sacrifice. However, the position he analyses starting from 3:08, I think I am missing something.

Kasparov vs Karpov, 1990 World Finals

[FEN "r3qb1k/1b4p1/p2pr2p/3n4/Pnp1N1N1/6RP/1B3PP1/1B1QR1K1 w - - 0 1"]

1. Nxh6 Rxh6 2. Nxd6 Qxe1+ 3. Qxe1 Rxd6 4. Qe4 Nd3

What if black plays

[FEN "r4b1k/1b4p1/p2r4/3n4/Pnp1Q3/6RP/1B3PP1/1B4K1 b - - 0 1"]

1... Nf6

instead of Nd3? Can't he both attack queen and defend h7 square? His chances of survival is so low, obviously, but I think Nf6 is better than Nd3, and worth analyzing.

Nf6 is followed by e.g.:

[FEN "r4b1k/1b4p1/p2r1n2/8/Pnp1Q3/6RP/1B3PP1/1B4K1 w - - 0 1"]

1. Qh4+ Kg8 2. Bxf6 Rxf6 3. Qxf6

with not only huge material advantage for white, but also some very nasty threats that are ultimately not defendable. So in short, there is not much to gain with Nf6.


scid vs pc interface I am having an issue setting up scid vs pc. I see tons of tutorials and they all show a nice interface with the board, analysis, and other windows all visible on one view. However all I get get is the board showing and the current few moves. Everything else is on separate tabs. I have searched high and low through the menus and options and Google  searches but no answers.  I tried to upload the screenshot urls but only one will post, if I ad the second one it deletes the 1st one.  Thank you.

Try setting Options -> Windows -> Dock Windows.  If I understand your problem correctly, that may fix it.


Is there a Open Source or Shareware Legal Move Checker Executable? Background:  I wrote and use a custom macro in the NoteTab Pro text editor to convert PGN position analysis to XML.  The resulting XML is used on my website to display chess puzzles.  I need to check for legal moves in some cases.  For example, a PGN move might say Rd6 in a position where two rooks can move to d6, but only one of them can legally move to d6 because the other is pinned to its King.  I am disinclined to write a macro legal move checker due to the apparent complexity of the task.  I do not want to reinvent the wheel.

Ideally, I am looking for an executable that can be called with FEN and next-move parameters, and return a positive or negative result based on the move's legality.

Simple problem. python-chess is a useful Python package that can do it for you easily. You will need to get a FEN, check if your move is a legal move.

  https://pypi.org/project/python-chess/

has everything you want.


Can white really not win this rook endgame? When playing against a player rated ~2500 Stockfish 8 managed merely to draw when playing white. This was the endgame before the draw (the draw occurred because it was king vs. king in the end).

Black played rook to h7 and then Stockfish played the rook to a7.

According to the Shredder database (sorry, I can't link directly to a position), the position after Rh7 is won in 32 moves and Ra7 gives the win away.

There are some similar positions with a- and b-pawns which are drawn, but this is not one of them. Actually, playing around with the database, I found that the initial position with the black king on b8, is drawn (and Rh7 is one of the two moves keeping the draw).

Another example is this one, where the white rook is tied to the defense of the b pawn and the white king can't really help.

[White "J. van der Wiel"]
[Black "P. Boersma"]
[Result "1/2"]
[FEN "8/2k5/1R6/PP5r/8/4K3/8/8 w - - 0 1"]

1. Ke4 Rh4+ 2. Kf5 Rh5+ 3. Kg6 Rc5 4. Kf7 Rh5 5. Rc6+ Kd7 6. a6 Rxb5 7. a7 Ra5 8. Re6 Kc7 1/2-1/2

source: Fundamental Chess Endings by Müller and Lamprecht


Are there rules for categorising all pawn-only endgames into won/drawn/lost? If a situation containing only pawns and kings is displayed is there a simple set of rules for determining if the position is won/drawn/lost?

I know for single pawn and double pawn endgames this is true with rules like the opposition, rule of square, rook pawns etc.  My question is, does this extend into multipawn games or are they simply too complex and varied?

Another way of putting the question might be: if you show two grandmasters a pawn only endgame; do they both immediately know the outcome, or are there some that they would need to play out?

Generally speaking, the side with the most pawns will win. The tempo provided by the extra pawn is usually enough to gain opposition and access to the key squares. Doubled pawns don't matter for this, unless they're blocked. The extra pawn can also limit the movement of the opponent's king, resulting in the possibility of a triangulation maneuver.

Another recurring theme/rule is the breakthrough. Grandmasters know the patterns for which a breakthrough is possible by heart.

But generally, multi-pawn endgames are just as complicated as other endgames. There is a Russian endgame study composer, Nikolai Grigoriev, who is famous for his pawn endgame studies. They truly show the rich possibilities of chess with just kings and pawns. With so many beautiful studies available, you know that there can be no general rule to determine the outcome.


Why don't I have more success with the King's Indian Attack? My last opening of choice as White was the King's Indian Attack to avoid having to learn a lot of opening lines, it being a system opening.  I've read Eric Schiller's and Ken Smith's books on the KIA.  I get the planned control of e5 and the desired strong piece and pawn presence on the kingside for an attack but rarely seem to be able to bring home the point.  The sample games I look at always seem to find strong continuations.  Am I just seeing the successful games?  Does this suggest basically a tactical shortcoming on my part, or could I be missing something else critically important that I need to know about the opening for complete understanding? I seem fairly tactically astute in open games. I might add that I haven't been particularly successful with the companion King's Indian Defense either.  Maybe positional play just isn't my forte.

The following game is the most recent KIA from several days ago against the computer, which although flawed by the blunder on move #30 yet will illustrate what I'm talking about.

[FEN ""]
[White "Conero"]
[Black "SparkChess"]

1.Nf3 g6 2.d3 d5 3.Nbd2 Bg4 4.g3 Bxf3 5.Nxf3 e6 6.Bg2 Nf6 7.O-O Bg7 8.c3 O-O 9.Qc2 Nc6 10. Bf4 b5 11.e4 Ng4 12.Rad1 f5 13.Rfe1 fxe4 14.dxe4 Nf6 15.e5 Nd7 16.h4 a5 17.a3 a4 18.Bh3 Nc5 19.Ng5 Qe7 20.Qe2 Rab8 21.h5 h6 22.Nf3 gxh5 23.Nd4 Qe8 24.Nxc6 Qxc6 25.Qxh5 Qe8 26.Qg4 h5 27.Qg5 Ne4 28.Qh4 c6 29. f3 Nc5 30.g4? Rxf4 0-1

Am I just seeing the successful games?

Of course! If you were writing a book trying to sell / promote a particular opening you wouldn't call it something like "How to Lose with the KIA". Nor would you fill it full of games where white played the KIA and lost. You'd fill it full of games where white won.

  I get the planned control of e5 and the desired strong piece and pawn
  presence on the kingside for an attack but rarely seem to be able to
  bring home the point.

Hey! You know what? That's chess. It's a pretty even game. The thing is, every time you move your opponent gets a move too. There is no forced win for white from move one and nor is there a forced win for either white or black at the end of the "book" part of almost all openings.

Your realistic aim should be to get a good playable position out of your chosen opening with white, a position you feel comfortable in, one where you know and understand the plans that follow from that particular opening. Then it's an even game. If your opponent understands the position and plays it better than you then he will likely win. If not and you both play it with equal understanding and ability it will be a draw. Only if you play the resulting positions better than your opponents will you win.


Why not 4.e3 Bxc3+ in the Nimzo-Indian? Why is 4.e3 Bxc3+ almost never played in the Nimzo-Indian, with idea of 5.bxc3 c5, considering that this is a relatively feared move after 4.e3 c5 5.Nf3 Bxc3, et cetera (Huebner Variation), so that a lot of White players switched to 5.Ne2 to avoid this system in recent times?

[fen ""]
[title "Nimzo-Indian Defense with 4. e3 Bxc3+"]
[startply "7"]
[startflipped "1"]

1. d4 Nf6
2. c4 e6
3. Nc3 Bb4
4. e3 Bxc3+
5. bxc3 c5

Same question from a different perspective: is one tempo that important in a relatively closed position? (e.g. 4.a3 Bxc3+ is generally considered a good game for Black). Then why shouldn't it be after 4.e3 Bxc3?

In this case, one tempo is important due to the concrete nature of the current position. White doesn't have to use it to play Nf3:

4.e3 Bxc3 5.bxc3 c5 6.Bd3, and if Black plays in the style of the Huebner with 6...Nc6 then White has 7.Ne2! and now 7...d6 8.0-0 e5 9.Ng3! gives White an edge (Stockfish says around +0.60). His knight controls the key e4- and f5- squares, and an f4 push is coming soon. This position is a major improvement for White over the normal Huebner system, where instead of playing Ne2-Ng3, White plays Nf3-Nd2 (to avoid Black's threat of playing the ...e4 fork). A knight on g3 can become an active attacker on the kingside, while a knight on d2 just blocks in the c1-bishop.

Note that if Black refuses to play in the style of the Huebner (6...Nc6, 7...d6, 8...e5) then White plays an early e4 push and gets a crushing position in the centre.


Converting from Algebraic notation to Coordinate notation I saw this thread: Converting square notation to algebraic notation programmatically

Unfortunately, it's the reverse of what I need to do.

Given a FEN and an Algebraic move, I need to generate the coordinate notation of said move.

I realize that you need the position (FEN) in order to reverse engineer the starting position of the pawn/piece being moved.

I'm hoping there is some utility or library/function that does this. If not, a description/outline of the basic algorithm would be great too.

You can do this easily in python using the python-chess module and using the parse_san function of chess.Move.

Let's call the script algebTocoord.py:

import chess

testfen = 'rnbqkb1r/pppppppp/5n2/8/3P4/8/PPP1PPPP/RNBQKBNR w KQkq - 1 2'
board = chess.Board(testfen)
algmove = 'Nf3'
coordmove = str(board.parse_san(algmove))
print coordmove

the printed output is:

'g1f3'

This was tested using Python version 2.7.16 and the 0.22.1 version of python-chess.


Attacking as Black in the Caro-Kann Is it possible to play the Caro-Kann aggressively/tactically as Black?
What are the attacking chances/ideas for black in the Caro-Kann? Or is it simply the wrong opening for that?
I found a few example games, where Black is crushing White in an attack on the king, e.g. in this grandmaster game: https://www.chessgames.com/perl/chessgame?gid=1103209

In the Caro-Kann, white dictates the speed and sharpness of play.  The exchange Caro-Kann typically shies away from tactical/aggressive positions.  In the advance bf5, white can play h4 which leads to very aggressive, open, and tactical games for both white and black.  You're likely looking for the Advance c5 which is a little more forcing for black that you're likely to get a tactical game.
Honestly, you're probably looking for a different answer to e4 if you want to play an aggressive game against white every time.  The Latvian Gambit is losing for black with correct play but if you know the lines, it's easy for white to go wrong quickly.


Why does the game end at checkmate and not upon taking the king? Ever since I was a kid this has felt kind of odd to me. Victory in chess is achieved by "cornering" the king, and not by taking him outright, like what you do to all the other pieces. I always wondered why that is.

Of course the distinction between taking the king and "cornering" him is very minute, and upon achieving checkmate you can confidently assume that a capture will occur next turn, but somehow it feels odd that this next step is forbidden by the official rules. What if the player who achieved check-mate is inexperienced or distracted and doesn't realize that he did so? What if he's really experienced and wants to continue taking material for sadistic purposes? Why do the rules of chess disallow such moments? These moments probably wouldn't end up happening in tournament games (since most seem to end up in resignation anyway), but nevertheless they could, and I think chess would be more fun like that. So why was the checkmate created?

Per wikipedia, citing Henry Davidson's A Short History of Chess (1949):

  In early Sanskrit chess (c. 500–700) the king could be captured and
  this ended the game. The Persians (c. 700–800) introduced the idea of
  warning that the king was under attack (announcing check in modern
  terminology). This was done to avoid the early and accidental end of a
  game. Later the Persians added the additional rule that a king could
  not be moved into check or left in check. As a result, the king could
  not be captured, and checkmate was the only decisive way of ending a
  game.


Minimax with alpha-beta pruning for chess I am creating a chess AI using the minimax method with alpha-beta pruning. I am trying to understand how the alpha-beta pruning works, but I can't get my head around it when it comes to chess where you set a certain search depth.

How do minimax with alpha-beta solve sacrificing a piece for advantage 2-3 moves ahead? Won't it just look at the position at the sacrifice and immediately discard that branch as bad, therefore missing the good "sacrifice"?

I thank you in advance for any clarifications or advice on improvements. Here is my code so far:

def minimax(board, depth, alpha, beta, maximizing_player):

    board.is_human_turn = not maximizing_player

    children = board.get_all_possible_moves()

    if depth == 0 or board.is_draw or board.is_check_mate:
        return None, evaluate(board)

    best_move = random.choice(children)

    if maximizing_player:
        max_eval = -math.inf
        for child in children:
            board_copy = copy.deepcopy(board)
            board_copy.move(child)
            current_eval = minimax(board_copy, depth - 1, alpha, beta, False)[1]
            if current_eval > max_eval:
                max_eval = current_eval
                best_move = child
            alpha = max(alpha, current_eval)
            if beta <= alpha:
                break
        return best_move, max_eval

    else:
        min_eval = math.inf
        for child in children:
            board_copy = copy.deepcopy(board)
            board_copy.move(child)
            current_eval = minimax(board_copy, depth - 1, alpha, beta, True)[1]
            if current_eval < min_eval:
                min_eval = current_eval
                best_move = child
            beta = min(beta, current_eval)
            if beta <= alpha:
                break
        return best_move, min_eval

In alpha/beta pruning, you only prune when further search cannot affect the outcome. In particular this means there will be no loss of information when you transition from MinMax to alpha/beta. There is only upside to alpha/beta (in contrast to other, more aggressive pruning methods).

The fundamental idea of alpha/beta pruning is that once you discover a branch to be inferior, there's no sense in figuring out exactly how inferior.

Here's how we'll do it: (When not using NegaMax) You can think of alpha as the maximum of all white (maximizing) ancestor's max_eval, and beta as the minimum of all black (minimizing) ancestor's min_eval.

Now, say you're searching a white node, w, and you discover the max_eval to be larger than beta. White is maximizing, so we know that the value of w can only go up. Then we are guaranteed that the value of w is larger than beta.

This means that this (white) node must have a (black) ancestor with min_eval smaller than the value of w, by definition of beta. Let's think more about this: because that black ancestor has min_eval smaller than w, it is guaranteed the option of a move with value min_eval. But w has value larger than min_eval. That black ancestor will always choose the lower one, so it doesn't matter how much larger w is. From the perspective of that black ancestor, w and w+100 are the exact same: worse.

Then, there's no reason to continue searching w: it can't possibly affect the outcome of the algorithm, so we prune the tree.

This is the only situation in which the alpha/beta algorithm prunes: when the outcome of further search cannot possibly affect the result.

If all of that is confusing, I really don't blame you. This is a topic that deserves lots of pictures and a few pages of explanation, not a few paragraphs. imo there aren't any great resources online, but if you (or anyone else) would like to contact me, I have something that might be helpful.


Any reference material on the Franco-Benoni defense? The Franco-Benoni defense is characterized by the black moves:
[fen ""]
[startply "4"]

1. e4 e6 2. d4 c5

The books I've read on the French defense contain none or very little information about this opening. Are there any "authoritative" or "main line" references or books that investigate this opening? Are any of you using this opening in your games? Where do you get your information from?

There is a book on the Franco-Benoni. (Using the alternative name "Barcza-Larsen")
It's rather old (1991) but I would guess theory doesn't move that quickly in the Franco-Benoni. It's probably a good way to get started, but you might want to check the lines with an engine.
Edit: There is also a short article by Harding on chesscafe.com.


Move first, record later; or vice-versa? Is it better to teach young players to record their move first and then make it?  Or should they be taught to move first and write later?  Is one considered better etiquette over the other?

It hasn't always been so, but these days (at least according to FIDE rules) it's illegal to write your move down before making it, outside of some situations in which a draw is being claimed or the game is being adjourned. Here are the exact details as to when a move should be recorded (with the most relevant part italicized):

  8.1.
  In the course of play each player is required to record his own moves and those of his opponent in the correct manner, move after move, as clearly and legibily as possible, in the algebraic notation (See Appendix C), on the scoresheet prescribed for the competition.

  It is forbidden to write the moves in advance, unless the player is claiming a draw according to Article 9.2, or 9.3 or adjourning a game according to the Guidelines of Adjourned Games point 1.a.

  A player may reply to his opponent’s move before recording it, if he so wishes. He must record his previous move before making another.

I believe the reason that it's against the rules now is because writing the move in advance could be construed as some sort of analysis aid. (I'm not arguing that that's a good reason for the rule; it's just what I understand to be a rationale for the rule.)


How many games should one play online per day or week? I participated in a tournament on chess.com and I have to play like 12 games, 3 days per move, although it's plenty of time, I can't concentrate, I noticed that when I play many games, I lose because I make mistakes.

The thing is when you have 12 games to be played, you often find yourself, not playing at all or playing all the games simultaneously, to just get over with it, and do something else other than playing chess.

So in an ideal situation, what is the best number of games to be played per day or week for average users?

A side question, is it good to play such tournaments? I mean when you have many games to be played, you'll lose concentration (at least I do) so isn't it better to play live tournaments (15 or 30 min for each player) isn't that a better way to concentrate on the moves?

Since playing chess is not a job for most of us, it may not make much sense to ask how many games should you play. Some people relish the adrenaline rush of 1 minute chess, some can play for hours, some like to play three games at once... and then some others like to play once a week. The answer depends on who you are, but since it seems that online tourneys stress you out, it may be better for you to attend live ones.

I know this is not much of an answer, but I think it is closest to the truth.


Strong chess program for GNU/Linux with a command line interface? I'm looking for a strong chess program for GNU/Linux with a command line interface, or one that I can alter to make it suit my needs

After a quick search, I found the question Chess program for Linux/Unix console, which gives some programs that are either too slow or too weak (with no command line though, it was on terminal, but that is easily manageable).

I wrote about Stockfish in the link you had. I don't see there is any engine better than that.


Which countries have the most GMs per capita? This interesting site has a "World map of chess grandmasters" which looks like this:

Apart from the fact that Russia is very wide (it looks like it crosses 10 time zones), it looks like Iceland has more GMs per capita than Russia. This is a nice picture but doesn't give the figures.
So, what are the top 50 countries ranked by GMs per million? And how does that change if you make it GMs per thousand players (FIDE registered players)?

Here are the results of queries on the latest (April 2021) FIDE rating list.
Interesting to note that Iceland is actually only in 2nd. I guess in the map in the question Monaco is too small to see. The first big country (population > 1 million) is Armenia in 5th. Russia, the country with the most GMs - 240, is only in 31st place. No sign in this list of China or India.
Country - GMs - GMsPerMillion

Monaco - 3 - 79.4
Iceland - 13 - 39.1
Andorra - 2 - 27.9
Faroe Islands - 1 - 20.3
Armenia - 40 - 13.3
Montenegro - 6 - 9.6
Georgia - 30 - 8.0
Croatia - 30 - 7.1
Serbia - 50 - 7.0
Latvia - 11 - 5.6
Hungary - 53 - 5.4
Slovenia - 11 - 5.3
Israel - 44 - 5.2
Macedonia - 10 - 4.8
Bulgaria - 33 - 4.58
Estonia - 6 - 4.57
Czech Republic - 34 - 3.2
Norway - 16 - 3.1
Lithuania - 8 - 2.8
Azerbaijan - 26 - 2.7
Mongolia - 8 - 2.6
Denmark - 14 - 2.5
Cuba - 27 - 2.4
Slovakia - 13 - 2.4
Netherlands - 38 - 2.24
Sweden - 22 - 2.23
Bosnia Herzegovina - 8 - 2.1
Ukraine - 87 - 2.0
Belarus - 17 - 1.78
Moldova - 6 - 1.68
Russia - 240 - 1.64
Scotland - 7 - 1.31
Greece - 14 - 1.29
Poland - 49 - 1.27
Qatar - 3 - 1.24
Spain - 57 - 1.23
Germany - 95 - 1.17
Switzerland - 9 - 1.08
Romania - 21 - 1.06
Turkmenistan - 5 - 1.05
Austria - 9 - 1.03
Kazakhstan - 15 - 0.85
Belgium - 9 - 0.796
France - 51 - 0.791
Finland - 4 - 0.727
Singapore - 4 - 0.723
England - 36 - 0.679
Paraguay - 4 - 0.584
Uruguay - 2 - 0.575
Uzbekistan - 17 - 0.548

When you look at GMs per thousand FIDE registered players the picture changes. Armenia moves to the top and China appears in the list at no. 5.
FullName - Players - GMs - GMSPerThousandPlayers

Armenia - 1789 - 40 - 22.4
Monaco - 136 - 3 - 22.1
Qatar - 147 - 3 - 20.4
Andorra - 151 - 2 - 13.2
China - 3783 - 48 - 12.7
Macedonia - 1048 - 10 - 9.54
Georgia - 3377 - 30 - 8.88
Cuba - 3080 - 27 - 8.77
Israel - 5316 - 44 - 8.23
Turkmenistan - 606 - 5 - 8.25
Bulgaria - 4512 - 33 - 7.31
Scotland - 994 - 7 - 7.04
Uzbekistan - 2417 - 17 - 7.03
Belarus - 2648 - 17 - 6.42
Montenegro - 1031 - 6 - 5.82
Iceland - 2244 - 13 - 5.79
Ukraine - 15318 - 87 - 5.68
United States - 18067 - 96 - 5.31
Moldova - 1139 - 6 - 5.27
Azerbaijan - 5223 - 26 - 4.98
Serbia - 10151 - 50 - 4.93
Hungary - 11116 - 53 - 4.77
Netherlands - 8152 - 38 - 4.66
Tajikistan - 232 - 1 - 4.31
Vietnam - 2996 - 12 - 4.01
England - 9464 - 36 - 3.80
Canada - 4059 - 14 - 3.45
Mongolia - 2331 - 8 - 3.43
Latvia - 3284 - 11 - 3.35
Paraguay - 1210 - 4 - 3.31
Sweden - 6694 - 22 - 3.29
Estonia - 1853 - 6 - 3.24
Croatia - 9292 - 30 - 3.23
Bosnia Herzegovina - 2794 - 8 - 2.86
Russia - 96262 - 240 - 2.49
Faroe Islands - 404 - 1 - 2.48
Czech Republic - 14000 - 34 - 2.43
Norway - 6671 - 16 - 2.4
Germany - 39740 - 95 - 2.39
Argentina - 10001 - 23 - 2.3
Finland - 1781 - 4 - 2.245
Slovenia - 5201 - 11 - 2.11
Philippines - 6200 - 13 - 2.1
Australia - 4824 - 10 - 2.07
Romania - 10165 - 21 - 2.066
Switzerland - 4528 - 9 - 1.99
Denmark - 7074 - 14 - 1.98
Kazakhstan - 8056 - 15 - 1.86
Lithuania - 4575 - 8 - 1.75
Poland - 28878 - 49 - 1.7


How do I politely ask a spectator to stop watching my game? I was playing a chess game with a highly rated person in a tournament, and his dad was watching over the game. Obviously, it didn't affect the game, but I would have felt better if he was not watching over the game. Should I just deal with him being there? How do I politely ask a spectator to not watch the game I am playing?

Inform the arbiter that it's affecting you, that's more or less all you can do.

Other players in the playing hall and spectators if they're allowed in are allowed to watch your game. But not to interfere with you or distract you.

So if the spectator goes over the line, the arbiter can tell him to take more distance, or leave the playing area. But by itself the fact that he is watching isn't enough, I'd say.


Why does this puzzle offer f8=R as better than f8=Q? Here's a chess puzzle that gave a confusing response.
https://chesspuzzle.net/Puzzle/52112
[FEN "5R2/1p6/p4Ppk/3r4/7p/1P6/P7/1K6 w - - 0 1"]

1. Rh8+ Kg5 2. f7 Rf5 3. f8=R

If you play f8=Q in this final position, you will not fail the puzzle, but be told "There is a better move..." (f8=R).
It seems inevitable that the black captures the promoted piece, and the result is the same after white recaptures.
Incidentally, f8=Q was played in the game. https://www.chess.com/games/view/15563079
What is more curious, is that I have played other puzzles on this site that allow multiple moves in a position for continuation, and my assumption therefore was that it only suggests a "better move" when your move doesn't change the theoretical outcome of the game, but gives significantly lower advantage (i.e. still decisively winning, but slower).  This would suggest that chesspuzzle.net has evaluated f8=Q to be an inaccuracy of some sort.
Is there any reasoning to be found for this?  Or is it just a strange computer evaluation?
I have tried inputting the position on the analysis board on lichess.org, and it flip flops between the two moves as the depth builds, but eventually starts showing f8=Q with a consistent advantage. (The opposite of chesspuzzle.net)
This seems strange also, as in my perhaps naïve reasoning explained initially, both moves should be identical.

If anything, promoting to a queen is the better choice, as it forces Black to exchange their rook. For promoting to a rook, Stockfish NNUE actually slightly prefers moving the f5-rook away instead of playing ...Rxf8 (although any continuation gives White a large winning advantage). So at the very least Black is given a choice.
But even if we were certain it's best for Black to play ...Rxf8 if White promotes to a rook, there would still be no reason to say that promoting to a rook is better than promoting to a queen - both lead to the same outcome. What possibly happened is that the site's computer calculated one line further/differently, and arrived at an evaluation that was higher in the line for promoting to a rook. Although since you said the site allows multiple solutions to sometimes be accepted, this seems like a bug in their software.


What is the best way to improve Crazyhouse or Bughouse skills? I have been playing Chess variants for a while now, and I would like to know how to improve my skills in bughouse and crazyhouse. Does anyone have any tips or strategies that would apply to either? Any input would be very helpful.

Since there isn't much material out there to study, the best way is to play with better players.  Of course, studying tactic problems is great for chess and the variants. FICS (free internet chess server) is probably where the best Siamese (bughouse) players are.

It helps if you have some opening systems worked out (since in Siamese being ahead on the clock can be crucial).
Published tips are here: http://www.freechess.org/Help/HelpFiles/bughouse_strat.html
https://www.chess.com/blog/Sorsi/advanced-bughouse-tips


What motivates you to play chess and continuously get better at it? I notice that many chess player, especially kids lose their ability to motivate themselves, especially because of the highly commercialization of the game. It seems as if playing for fun today isn't very relevant, and people disappear out of the game.

There are 4 motivations to playing the game, which will vary by person:

Aesthetic appeal: Some players are motivated by compositions where paradoxical moves are required. Others are motivated by sweeping combinations or profound ideas. Recall the feeling that you had the first time you saw a smothered mate. This is the aesthetic motivation
Competitive struggle: Some people are motivated to win, to show their supremacy at the board. Or they are motivated to show their fighting spirit or tenacious defensive abilities against strong opposition. They might be motivated to win a trophy or prize money. These are the kinds of people who see chess as a sport primarily
Personal improvement: For myself, I was drawn to chess because I wanted to improve my concentration. Others are drawn because they want to develop a way to think logically that they can apply elsewhere in their lives. Others do it to develop their memory
Fun: Contrary to your post, many people just play for the fun of it! For example, when I held a chess club in my workplace during lunch, people sacrificed liberally, took big risks and (heaven forbid) had a chat whilst playing!

Each person is likely to have a combination of these motivations.


Is it true that at any time only one piece can put king in check? I am writing a simple chess game in which I have to determine the end game conditions. My algorithm requires the piece that is putting the opponent king in check, and checks the following:

King cannot escape
Piece cannot be eliminated
Path cannot be blocked

If all three conditions satisfy, then it is checkmate. However, I am wondering if there can be more than one piece simultaneously putting a king in check. It doesn't seem to be possible, but I can't come up with a proof for it. For example, is it possible for 2 rooks to put a king in check at the same time? Personally, I don't think that it's possible.

Double check is a fine tactic. An example would be a bishop lined up on the same diagonal as the king with a rook or knight in the way blocking the check. The rook or knight moves giving check to the king and also uncovering the check from the bishop. The king must move since there is no way to block two different lines or take two different pieces at the same time.


Looking for analysis or games of top players in less known, perhaps a bit dubious but aggressive lines in the Ruy Lopez from Black's point of view When my opponent plays 1. e4 I reply with 1... e5. When the game shifts to Ruy Lopez after 2. Nf3 and 3. Bb5 I respond 3... f5. Although this opening is to my taste, I am not reluctant to learn more about chess and Ruy Lopez. I've heard an anecdote that a deceased GM once said that playing the Ruy Lopez can improve your chess overall. With that in mind I am into playing the Ruy Lopez, but preferably lines that

don't require white to cooperate that much
are sharp, possibly dubious
deviate from mainlines such as Breyer,  Berlin, d3, Marshall, Chigorin, Zaitsev etc.

There are a couple of games between AlphaZero and Stockfish. The authors of the book Game Changer about AlphaZero, GM Matthew Sadler and WIM Natasha Regan, analyse the opening phase of these two games in this YouTube video.
Here are the opening moves from the two games, first with AlphaZero playing black and coming up with a new idea, castling queenside and pushing the h pawn.
[Title "Stockfish vs AlphaZero"]
[fen ""]

1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.Nc3 fxe4 5.Nxe4 Nf6 6.Nxf6+ Qxf6 7.Qe2 Be7 8.Bxc6 bxc6 9.Nxe5 Bb7 10.O-O O-O-O 11.d3 Rde8 12.Nc4 h5 13.Qe3 h4 14.Qh3 Kb8 15.Bd2 d5 16.Bc3 d4 17.Bd2 Bc8 18.Qf3 Qxf3 19.gxf3 Be6

And then with AlphaZero playing white and again getting very aggressive
[Title "AlphaZero vs Stockfish"]
[fen ""]

1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.d3 fxe4 5.dxe4 Nf6 6.O-O d6 7.Bc4 Bg4 8.h3 Bh5 9.Nc3 Qd7 10.Nd5 O-O-O 11.Qd3 Kb8 12.a4 Ne7 13.Ng5 Bg6 14.Nxf6 gxf6 15.Nf7 Bxf7 16.Bxf7 h5 17.a5 a6 18.Qb3 Nc6 19.Be3 Bh6 20.Be6 Qg7 21.Bd5 Qd7 22.Ra3 Bxe3 23.fxe3

Then there are these two YouTube videos where GM Melik Khachiyan analyses some of his games in the Schlieman -
Part 1
Part 2
Finally Kingscrusher analyses the historic game Bobby Fischer vs Milan Matulovic - Herceg Novi Blitz 1970 on his YouTube channel.


Is White checkmated? Does Black's pinned knight on g4 protect the bishop on f2 from the white king?

B2N4/8/3p2p1/Q2P4/4R1nk/7b/PPP2bpP/1R4K1 w - - 0 1

This is checkmate.

According to the fide rules (bold by me):

1.2
The objective of each player is to place the opponent’s king ‘under attack’ in such a way that the opponent has no legal move. The player who achieves this goal is said to have ‘checkmated’ the opponent’s king and to have won the game. Leaving one’s own king under attack, exposing one’s own king to attack and also ’capturing’ the opponent’s king are not allowed. The opponent whose king has been checkmated has lost the game.

3.9
The king is said to be 'in check' if it is attacked by one or more of the opponent's pieces, even if such pieces are constrained from moving to that square because they would then leave or place their own king in check. No piece can be moved that will either expose the king of the same colour to check or leave that king in check.


Was this considered a stalemate? I'm new at chess and still learning the rules. The other day I was playing a friend of mine, and it got to the point where I had only my king and queen and he had only his king and bishop. I forgot the exactly how we got to this point, but when we did, he said it would be stalemate and result in a draw. I argued that we keep playing and I wound up putting him in checkmate. He didn't make any fatal or illegal moves; I just beat him. My question is, why would this be a draw if I could win? Everything I find says that when either side has only a king and bishop/knight it results in a draw. Of course I may have misunderstood, but it seems like one side can get punished for simply taking out the other sides pieces.

If I understand well you had a king and a queen, and your opponent a king and a bishop.

It is not a stalemate nor a draw, unless you reach a position like this one, for example:

[fen "8/8/8/8/8/6K1/8/5Qbk b - - 0 1"]

A stalemate occurs whenever the player having the turn has no legal moves and he's not under check.

A draw happens when there's no sequence of legal moves (even if they are absurd ones) than can lead to a checkmate, when the same position is repeated at least three times, or when at least 50 moves have been done without a pawn move or a capture.


Is this position a forced win for Black after move 14? In this Lichess game,

[FEN ""]

1.c4 e5 2.e4 d6 3.Nc3 Be6 4.Nf3 Nc6 5. d4 exd4 6.Nxd4 Nxd4 7.Qxd4 c5 8.Qd3 g6 9. Be2 Bg7 10.O-O Nh6 11.Re1 Ng4 12.Bxg4 Bxg4 13.e5 Bxe5 14.Nd5 Qh4 15. Nc7+ Kd7 16. Nxa8 Qh2+ 17. Kf1 Qh1#

After move 14 White is facing a serious mate threat from the Queen on h4, Bishop on g4, and Bishop on e5. White goes with 15. Nc7+ , forking the King and Rook, but ignoring the mate threat. After the rook capture, Mate in 2 was assured.

Could white have avoided this mate? By playing, say, Qg3 or h3? Or do both of these positions lead to wins for black, hence, white's strategy with 15 Nc7+ was to prolong mate and perhaps prod black into an unforced error?

The best move would have been 16. Rxe5, which entirely eliminates the mate threat, leaving white with a winning advantage.

r6r/ppNk1p1p/3p2p1/2p1R3/2P3bq/3Q4/PP3PPP/R1B3K1 b - - 0 16

Here, if black takes the white knight (16. ... Kxc7), 17. Bg5 wins the queen as Qh5 is met with Bd8+.


What are signs of achieving Master strength? Although even Masters can play very badly at times, especially against other Masters, and apart from ELO ratings, how to you get the feeling that you are definitely of "Master" strength, and no longer of "Expert" strength?

If a player is truly stronger than you independent of his current form, he is able to outplay you even if you don't overlook a single important tactic. If he is in bad form he will probably overlook tactics himself and let you back into the game, but you will still be outplayed in the stretches between his little blunders.

Once you don't have this feeling anymore of drifting into trouble without knowing why when playing against master players, and once you are able to just outplay weaker players by hand, you can be pretty sure that you have reached a master's level of understanding. Your Elo should follow suit.


Deep Blue versus Magnus Carlsen? I have seen a lot of debate about who is better between Carlsen and Kasparov.

Could a match between Carlsen and the exact same Deep Blue configuration that beat Kasparov be used to settle this?

I'd say no. Playing against a human being is a lot different than playing computers. Here is an article (unfortunately, it is in Dutch) about a German player with a rating under 2100 who regularly beat the top chess programs, by playing strange openings and long-term sacrifices. This was a few years after the Kasparov - Deep Blue match.


What's the best plan for white in this position? I have come this far and am not sure what to do further in the game.  I have been doing some maneuvering here but it seemed quite disoriented.  What is a good plan that will help white win?

[FEN "2r2kr1/8/2b1p1q1/p2p1pP1/3P4/2N3R1/3QP3/2K2BR1 w - - 0 1"]

White should be winning in this position quite comfortably with the extra piece.

One relatively simple plan is to play 1.Rh3 in order to move the rook to h6 to push the passed g pawn.  If black moves the queen, then g6 is very strong.

For example:

1.Rh3 Bd7 (to defend the loose rook on c8)
2.e3 (Rh6 is not possible immediately because of Qxh6! winning both rooks for the queen) Qf7
3.Ba6 Rc7
4.Qb2 (Δ Qb8+) Bc8
5.Bxc8 Rxc8
6.Qa3+ (and next move white will take the Pa5)

Another plan is to play e3 in order to free the bishop (so that white can make use of the extra piece), but this is less ambitious than playing Rh3 immediately.


Do symmetric positions have a higher draw ratio? From my experience in chess, I have observed that my draw ratio in symmetric positions (e.g. the Italian opening) is higher than in non-symmetric positions (e.g. the Spanish opening or different gambits). In general, do symmetric positions have a higher draw ratio?

Very good question, +1 from me.

  Is it true that asymmetric leads to win or lose and symmetric leads to draw?

It is not true that symmetric positions lead to a draw, and asymmetric ones to winning.

EXPLANATION:

Many people consider the Exchange variation of the Slav defense as drawn, but you will find that top grandmasters disagree.

In a symmetric position White has a small initiative or pressure, because he moves first.

The reason this gives drawn games is because even if White manages to make some advantage, it is usually small and it pins Black to defense "but that is all". Without a second weakness White can not win, and with proper defense he usually can not create it.

However, try to play symmetric position as Black against a stronger opponent and you will see just how hard it is to draw. The advantage of having permanent ( although small ) initiative or pressure counts a lot, and I am telling you this from my experience.

Although I do not play against humans that often, I regularly play against Shredder in my spare time.

I always set the difficulty to hard and I always get "ground down" in the Exchanged Slav or in other semi-symmetrical positions-like 1.e4 e5.

I usually have an easier time drawing in asymmetrical positions, since the imbalance of strengths/weaknesses gives strong counter-play for both sides.

In the Queen's Gambit Declined-Exchange variation I usually draw way easier, although I do not know much of its theory.

The difference between symmetrical and asymmetrical positions is this:

In symmetric ones you have a small but permanent advantage as White. That means that you can win, draw or lose, while Black usually can only draw or lose. Here White needs to make an effort to outplay his opponent or else it will end as a draw. Hence in these positions a truly better player wins ( Black's position is harder to play, though).

In asymmetric positions both sides have strong counter-play so in these positions chances tend to be more equal. These positions are better for Black because you will have counter-play from the start while in the symmetric positions you will have to work very hard just to generate it-how many times did we all have "a won game" only to lose it because our opponent was "lucky to have that one saving tactical shot"?

Because asymmetric positions give greater chances for both sides to win you see them being more popular then symmetric ones. Also, they require less studying.

What I have noticed in the games of Karpov, Petrosian, Capablanca and many others is that they use simple positions that are objectively equal to outplay their opponents.

Symmetric positions can serve great for this-your opponent thinks that it is a draw, but believe me when I say this, that extra tempo in the hands of the stronger and more creative player does count and can solve the game! I use this method too, and this method was used on me, so I speak from my experience.

Other players like Alekhin, Kasparov, Tal and so on, did not care for giving their opponents strong counter-play because they relied on their fantastic calculation strength.

Objectively speaking, if both play well, the game must end in a draw. It is a matter of choice how someone will fight for the win.

I prefer symmetric positions as White, since I am good at endgame and positional play, so to have a small but lasting advantage is enough for me. I will use my creativity to complicate the game and generate winning chances. These positions require a lot of creative work and high technique for both sides to be able to play them well.

As Black, I always play asymmetric lines because of the reasons given above ( believe me, it is not so easy to draw against Shredder relying on "sheer" strength even if the position is drawn! ). These positions require a strong calculating skill from a player and crafty use of tempo.

Hopefully this answer sheds some light and gives you some insight about strength / weaknesses of both types of positions.

EDIT IN RESPONSE TO THE COMMENT FROM MEMBER SalvadorDali:

  Also sentence like asymmetric positions require less time to study sounds really strange.

The beauty of the asymmetric position is the strength of the counter-play you get and how little energy and time it requires to find a plan.

Let us compare two similar openings from Black's point of view-QGD and Slav-but let us focus on Exchange variations.

[fen "r1bqrnk1/pp2bppp/2p2n2/3p2B1/3P4/2NBPN2/PPQ2PPP/R4RK1 w - - 0 1"]

In QGD it is easier to find a plan as Black-knight jump on e4, a6 or a5 pawn push vs minority attack or c4 outpost, "Petrosian knight", king-side piece attack and so on-you can think of a plan "right off the bat". Same goes for White-Nge2 plan, minority attack and so on. All this happens due to asymmetry. The counter-play is strong for both-if Black succeeds White loses, and same happens if White succeeds in carrying his plan out. Furthermore, you have limited amount of ideas to study.

[fen "2r3k1/1prbbppp/pqn1pn2/3p4/3P4/P1NBPN2/1PRBQPPP/2R3K1 w - - 0 1"]

Now think about the Exchange Slav from Black's and White's point of view-can you offer a plan the same way? No you can not. This means that White will have to invest a lot of work to think of a plan that will give him more than a draw and that is not so easy to do in a nearly equal position. All you have here is an advantage of the first move which is enough for a small but lasting initiative but not for a win. However, in equal positions it is the strength and creativity of the both players that counts the most. One of the tries for White is to double rooks on the c-file and then enter voluntarily into IQP position.

[fen "2r3k1/1prbbp1p/pqn1p1p1/8/3PQ3/P2B1N2/1PRB1PPP/2R3K1 w - - 0 1"]

This will make an endgame weakness but due to his slight initiative, and now space advantage, he will retain some chances to win. Again, he will need to be creative to be able to win so he nigh decide to "equalize the position" by opening the center thus transforming the position into open one, where he will have slight mobility advantage.
Still, that is just an initiative-Black can still defend- so White will have to transpose into a better endgame but that requires a lot more knowledge-especially since the position is equal-so the art of properly exchanging pieces will be crucial here. Let us say that White somehow manages to enter knight vs white bishop endgame-since the center is open and pawns are not fixed it will be hard for him to win.

[fen "6k1/1p1b1p1p/p5p1/8/8/5N2/PP3PPP/6K1 w - - 0 1"]

He will again have to invest so much work in order to create winning chances, and will have to show inhuman technique so he can convert that advantage.

As for Black, he must adapt to White's action, and if White is creative player, that means you need a lot of knowledge as well to parry his threats. And what about generating counter-play that gives you equal winning chances in the above diagram? Good luck with that! In symmetric positions it is only White who can win.

What if I am 2550 ELO player with Black who plays against 2300 ELO White? If White knows his stuff he can draw easily-that is why GMs play the e6 move order instead of c6-QGD Exchange offers much easier play for a win. Think about the example for White I have described above, and tell me how would you generate winning chances? You will need an enormous amount of effort just to think of a plan, and high technique to carry it out. Not to mention the endgame technique required to outplay your opponent and convert the advantage. Same question for Black-how would you generate winning chances?

In symmetric positions-not only openings but middle and early endgames-you need a lot more work to generate tangible attack/counter-attack because everything is equal. You do not have a clear plan "right off the bat" and when you find one it is not as dangerous as it would be in the asymmetric position.

That still does not mean that I should settle with a draw. But to win in such positions you need to have every aspect of your game at a high level because you never know where will you get the chance to outplay the opponent-in the middle game or endgame or maybe opening-and even when you get that chance you still get an advantage you must "grind down" and that also requires high level of technique.

In asymmetric positions you have it so much easier-you do not need every aspect of your game to be at the high level ( this is especially true for the endgame! ) to be able to outplay your opponent. You only need high tactical skill and good knowledge of the typical plans ( minority attack, knight jump to e4 and so on... ) and you are good to go.

This brings me to the second part of your comment:

  Can you please clarify your experience a little bit deeper, I can understand such phrase from a GM, but sorry for my skepticism - but playing against computer program does tell nothing about your knowledge.

Although not so clear, I assume you think of this sentence:

Many people consider the Exchange variation of the Slav defense as drawn, but you will find that top grandmasters disagree.

Again, look at the example diagram for Exchange Semi-Slav and you shall see that only White can win. White has advantage of first move here and that really counts as he can unbalance the position first. He can change the position into Isolated Queen's Pawn or he can completely open the center.

Black can only sit and wait. Although he is not weaker, he is passive and although computers have no problem drawing this position it is extremely hard for a human to just "soak up" punch after punch just to draw-come on Rocky Balboa at least won at the end! :)

That is why GMs tried to introduce an early Qb6 with Black in order to unbalance the position and get some counter-play or at least to get real winning chances after their positional suffering ends-the idea is to snatch a pawn on b2 and "suffer" until the endgame comes. Some abandoned the c6 move order completely and enter Semi-Slav this way:

[fen ""]

1.d4 d5 2.c4 e6!? 3.Nc3 c6

The point of this move order is to enter the QGD exchange variation instead of Slav exchange if White exchanges on d5.

I do not recall exactly the line in the Slav-I belong to those who abandoned the c6 move order and play e6 but here is the idea with Qb6:

[fen "rnb1kb1r/pp3ppp/1q2pn2/3p4/3P1B2/2N1PN2/PP3PPP/R2QKB1R w KQkq - 0 1"]

If you have additional questions leave a comment.

Best regards.


Why would trading this bad bishop be a bad move? When running a game I played through the analysis engines, I get that my 12th move, 12.Ba3, was an inaccuracy (-0.3 -> -1.3).

Since my center pawns are on dark squares, I assumed my dark bishop was a bad bishop and trading it by black's dark bishop, that can also pin my knight on c3, would be a good idea.

What was wrong with this move? Is a tactical error or a strategic one, and why?

[fen ""]
[Event "Let's Play!"]
[Site "Chess.com"]
[Date "2018.05.15"]
[White "me"]
[Black "other"]
[Result "1-0"]
[ECO "C02"]
[WhiteElo "1472"]
[BlackElo "1492"]
[TimeControl "1/604800"]
[EndDate "2018.06.11"]
[CurrentPosition "r1b1kb1r/3q1pp1/ppn1p2p/3pPn2/P2P4/BPN2N2/5PPP/R2QKB1R b KQkq - 2 12"]

1.d4 e6 2.e4 d5 3.e5 c5 4.c3 Nc6 5.Nf3 Nge7 { C02: French Defense: Advance, Paulsen Attack, 5...Nge7 } 6.Bg5 Qd7 { (-0.51 → +0.17) Inaccuracy. A better move was 6... h6. } ( 6...h6 7.Bd2 7...Qb6 8.Qb3 8...Qxb3 9.axb3 9...cxd4 10.cxd4 10...Nf5 11.Ra4 ) 7.b3 h6 8.Bc1 cxd4 9.cxd4 b6 10.Nc3 a6 11.a4 Nf5 12.Ba3 { (-0.11 → -0.95) Inaccuracy. A better move was 12. Be2. } ( 12.Be2 12...Bb4 13.Bb2 13...O-O 14.O-O 14...Bb7 15.Rc1 15...Rfc8 16.Na2 16...Be7 ) 12...Nb4 { (-1.00 → +1.62) Blunder. The best move was 12... Bxa3. } ( 12...Bxa3 13.Rxa3 13...Qe7 14.b4 14...Nh4 15.Nxh4 15...Qxh4 16.a5 16...Qxd4 17.Qxd4 ) 13.g4 Nxd4 14.Nxd4 h5 { (+1.02 → +2.10) Inaccuracy. A better move was 14... Qc7. } ( 14...Qc7 15.Nce2 15...Qxe5 16.Bg2 16...Bc5 17.Qd2 17...Qd6 18.f4 18...a5 19.O-O ) 15.gxh5 { (+2.81 → +0.58) Blunder. The best move was 15. Ncb5. } ( 15.Ncb5 15...Qd8 16.Qd2 16...axb5 17.Bxb4 17...bxa4 18.Rxa4 18...Rxa4 19.bxa4 19...Bd7 ) 15...Bb7 { (+0.72 → +2.09) Inaccuracy. A better move was 15... Qc7. } ( 15...Qc7 16.Nce2 16...Qxe5 17.Bg2 17...a5 18.O-O 18...Ba6 19.Ng3 19...Bxf1 20.Bxf1 ) 16.Na2 Nxa2 17.Rxa2 Bxa3 18.Rxa3 Rc8 19.Ra1 { (+2.29 → +1.44) Inaccuracy. A better move was 19. b4. } ( 19.b4 19...Qe7 20.Qd2 20...Rxh5 21.f4 21...Qh4+ 22.Kd1 22...Kf8 23.Be2 23...Rh8 ) 19...Qe7 { (+1.36 → +2.49) Inaccuracy. A better move was 19... Qc7. } ( 19...Qc7 20.Be2 20...Qxe5 21.O-O 21...Qf4 22.Bg4 22...O-O 23.a5 23...bxa5 24.Rxa5 ) 20.Rg1 { (+2.56 → +1.50) Inaccuracy. A better move was 20. Be2. } ( 20.Be2 20...Qc7 21.Qd2 21...Qxe5 22.O-O 22...Qf6 23.f4 23...O-O 24.Qb4 24...Qd8 )  1-0

Tactics.

Trading dark-squared bishops is useful in the long run, but a4-Ba3 is a bit too slow to exchange the Bf8 that hasn't moved yet; Also you weakened the dark square b4 in the process. Black can take advantage of the misplaced Ra3 to attack the weak pawn on d4.

After 12...Bxa3 13.Rxa3 Qe7! {eyeing both a3 and h4}, any rook retreat or protection would allow 14...Qb4, when you cannot parry the simultaneous attacks on Nc3 and Pd4.

14.b4!? is slightly more stubborn but also lose a pawn to either 14...Nxb4 or 14...Nh4.

The game continuation, 12..Nb4??, on the other hand, deprived Black's Nf5 of any retreat square that wouldn't block the Bb8-Nb4 connection. Your smart retort, 13.g4!, won a piece.

By the way, earlier at move 10 you had a possibility to ensure the bishop trade without any weakening: 10.Ba3!? and trade on f8 once the Ne7 moves.


Is it possible to get DTM of a position from sygyzy tables? This is a programming question related to chess endgame tables.

As far as I know syzygy tables allow me to get WDL and DTZ information for a given position. Is it possible to somehow (without access to chess engine) extract DTM information of a position from these tables?

Based on what I understood from python chess documentation, that minimaxing the DTZ will give you a win, but it does not guarantee the quickest win:

  Minmaxing the DTZ values guarantees winning a won position (and
  drawing a drawn position), because it makes progress keeping the win
  in hand. However the lines are not always the most straightforward
  ways to win.

No. It's not possible. People use Gaviota tablebase if they want to do DTM or the old Nalimov.

Syzygy tablebase is the most popular tablebase algorithm because it doesn't do DTM, better compression. You can't get both - information and size.


How to improve my calculation and guess my opponents move I am a 1100 rated player.In rapid and blitz games I beated 1600 players this proves that my intution is good but at classical matches I can't even handle a 1300 player.I am a positional player as I just need a moderate advantage .But I am weak in long term calculation as I can't judge my opponent's move so kindly tell measures improve my calculation

You could make your question more specific, giving examples of when and what type of moves you fail to take into account. Anyway, I am 2050 and suffer from the same, so, it is a relevant concern for players of all levels! Start with distinguishing forcing moves, from non-forcing ones. Basically, unless you've given a check, your opponent can, in theory, play any move they wish. Thus, look for as many possibilities as you can afford the time for. My own problem: I tend to fool myself into believing that my opponent and I together are trying to produce a stunning, beautiful game! As if he/she will not ruin my beautiful strategy I have in mind, and they will help me carry it out!! "I attack this pawn and of course they will defend it..." And then I got the shocking response that sends chills down my spine, waking me up from my dream :))

Do not ASSUME that by default your opponent will respond in the way you think they should/must. Try to look for all possibilities on their behalf. Look for the strongest they can play.


Is this the only opening that allows one side to end up with three knights? In Queen's Gambit Declined, Albin counter-gambit, Lasker trap, black ended up with three knights, which should be rare. Here white should not capture the additional knight in the next move (8. Rxg1 Bg4+ and black is winning). Are there any other openings that one side ends up with three or more knights?

[FEN ""]
1. d4 d5 2. c4 e5 3. dxe5 d4 4. e3 Bb4 5. Bd2 dxe3 6. Bxb4 exf2 7. Ke2 fxg1=N

As @JossieCalderon pointed out, any opening could end up with three knights for one side. This would always require a knight promotion of some sort. Usually, knight promotions occur to

Give check to the opponent immediately to move the king to another square or to save a tempo.
Avoid a knight fork from the opponent, or give one of your own
Avoid stalemate
Give checkmate

I think, however, that you are also asking if there is another opening where knight promotion occurs in the opening phase of the game. The answer is  most likely "no".


How should I configure Stockfish if I want it to play as a 2800 ELO player without the UCI_LimitStrength value? Stockfish has so many parameters that I'm not sure which one I should change so that it has a strength equivalent to that of a human who has 2800 ELO, well that's one of my wishes, the other is to be able to play against Stockfish at its maximum potential (3600 ELO), it is clear that I will lose but I don't care, I just want to play, the specifications of my PC are as follows:
-4GB RAM
-CPU 4Cores/4Threads
-Only HDD
I have been testing with the Skill Level parameter however I am not sure if that is enough as I am not a very strong player to know if Stockfish is playing better than a GM.

So couple of issues off the cuff;
Do you have a particular version in mind?
Chess engines don't exactly have "ELOs". Chess engines are about calculation speed, calculation depth. They guestimate (at best) to determine a theoretical strength then measure against  other engines.
Stockfish 9 with 4 Cores is ~ 3200 "ELO"
Stockfish 12 similar rig I would argue is around that 3400-3600 "ELO" Mark.
The Reality; Playing solely against engines, at the highest level is ill advised for any development and engines are best used for position analysis (if that).


Tool that suggests tactics exercises based on game analysis Does anyone know of any common tool that can go throughout your game database (I have a couple of hundreds of my game's PGNs), and extract tactics that one should be training? I believe something as suggesting board positions related to blunders, missed mates in 1, 2, 3, missed forks, etc.

Both ChessBase and Fritz do this. I am not sure if others do it too, but this is a great feature of many products from Chessbase.

If you can pick up Chessbase, well and good. Otherwise look into Fritz that might be one version behind the latest version. They sometimes go on sale on Amazon.com and elsewhere.

Here's what you do:

You ask Fritz (or similar engine) to analyze your games.
Select the option that asks if it should create exercises during full analysis.
Once it completes the analysis (it can analyze all 200 of your games if you give it enough time), you can then play through the tactics from your own games.

ProTip: Players will sometimes subset only those games that have exercises, move it to a new database, and play through these exercises. You are essentially training on situations that occur in your own games, a great way to improve.

Hope that helps.


How many steps can a grandmaster foresee? What makes a grandmaster special? Is it the amount of steps the grandmaster can foresee, or the creativity? How many steps can a grandmaster foresee in average in a game (for instance Carlsen and Ivanchuk)? Is there a minimum amount?

This depends a lot on the position and cannot be answered generally. If you have a forced line, i.e. a position where there are only few candidate moves at every step, a grandmaster can calculate many moves. I am reluctant to give a concrete number because it really depends, but to give you a rough idea, let's say 20 moves.

On the other hand if the position is rather closed, of the maneuvering type, with many equal alternatives at every step, the calculation depth will be much smaller, simply because the number of variations will be much much larger in this case. And even if you calculated 20 moves deep you might not come to a conclusion on which line is best, because 20 moves in the future the position might still be equal. In this case a grandmaster would typically only calculate a couple of moves deep (if at all) in order to check that he is not blundering anything to a tactic.

As you can see from this description, pure calculation strength is only needed sometimes in a game and certainly not the only reason that grandmasters are much better than the rest. Unlike computers, humans do not play chess by calculating many moves in advance. The strength of human players over computers is that they can evaluate the position and develop a plan based on the evaluation. Humans focus more on recognizing patterns and play moves based on these patterns.

So, grandmasters are grandmasters, because they are good at all parts of the game:

calculating many moves ahead
evaluating a position correctly
finding the right plan
good at defense: using tactical ideas, standard methods, pure calculation...)
good at openings: knowing main lines, side lines, recognizing wrong moves in an opening and knowing how to react to them, knowing the ideas behind openings...
good at endgames: as with openings, there is a huge body of theory that you can study; also some grandmasters like Carlsen, are said to be particularly good at endgames beyond the known theory
pattern recognition abilities: to recognize tactics and other known motives
creativity
personal traits, physical fitness


Chess Engine with Python-Based / API? I went through the most popular chess engines, e.g. StockFish, Komodo, Rykba and so forth, but I wasn't able to a.) find an API or b.) a python based Engine - does anyone know a suitable project?
I want to implement a chess engine in a python-based gameportal I'm building (offering to analyse the game after the chess round), though it's an assigned project and I need to use purely Python (except graphics) for the project, hence I was either looking for a proper API or Python based Chess Engine - anyone knows an implementation?

Yes, there is a chess engine in Python: Sunfish
There is also a python library for chess: python-chess


Can you please help me analyse my game? [FEN ""]
[Event "?"]
[Site "?"]
[Date "2016.09.11"]
[Round "?"]
[White "Bright"]
[Black "Ogbe"]
[Result "1-0"]
[WhiteElo "?"]
[BlackElo "?"]
[ECO "C64"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 Bc5 4. Bxc6 dxc6 5. O-O Bg4 6. d3 Ne7 7. Bg5 f6     8. Be3 Bxe3 9. fxe3 O-O 10. Nc3 Ng6 11. h3 Be6 12. Qe2 Qd7 13. d4 b5 14. b3 Rad8 15. Rad1 exd4 16. exd4 Nf4 17. Qe3 Nxg2 18. Kxg2 Bxh3+ 19. Kh2 Bxf1 20. Rxf1 Qg4 21. Rg1 Qh5+ 22. Kg2 f5 23. e5 f4 24. Qe4 Rf5 25. Kf2 Qh3 26. Qxc6 g5 27. Qe6+ Kf8 28. Rxg5 1-0

I think after the knight sacrifice I should have doubled up my rooks and attack slowly. Please help me improve the options.

Overall:
The game was pretty drawish, leaning towards the black side, it was up to whose endgame was better. However, at the end, you took too much risks and lost due to that.

[FEN ""]
[Event "?"]
[Site "?"]
[Date "2016.09.11"]
[Round "?"]
[White "Bright"]
[Black "Ogbe"]
[Result "1-0"]
[ECO "C64"]

1.e4 e5 2.Nf3 Nc6 3.Bb5 Bc5 4.Bxc6 $6 {Minor comment: c3 and O-O are the moves that are studied, this throws away all advantage.} dxc6 5.O-O Bg4 6.d3 Ne7 7.Bg5 f6 8.Be3 Bxe3 9.fxe3 O-O 10.Nc3 Ng6 11.h3 Be6 12.Qe2 Qd7 13.d4 b5 14.b3 {Notice the weaknesses, save them and exploit them later in game. This is an example when you exploit them immediately[%draw full,c3,red][%draw full,b2,red] [%draw full,a3,red]} 14...Rad8 ( 14...b4 15.Na4 a5 16.c4 bxc3 17.Nxc3 )15.Rad1 exd4 $1 16.exd4 Nf4 17.Qe3 Nxg2 18.Kxg2 Bxh3+ { [%draw arrow,g2,f2,green]} 19.Kh2 Bxf1 20.Rxf1 Qg4 $2 {I suggest you start opening the board and exchanging pawns} ( 20...Qe6 {[%draw arrow,e6,a2,red][%draw arrow,a7,a4,red]} 21.Rg1 a5 22.Ne2 Rfe8 23.e5 fxe5 24.Qg5 Qe7 25.dxe5 Qxg5 26.Rxg5 Rd5 ) ( 20...Rfe8 21.Rg1 a5 22.Ne2 a4 ( 22...Qf7 {[%draw arrow,f7,a2,red][%draw arrow,a5,a4,red]} 23.Nf4 a4 24.Rg3 axb3 25.cxb3 Ra8 ) 23.bxa4 Ra8 24.axb5 Rxa2 25.bxc6 Qxc6 26.Qb3+ Qe6 ) 21.Rg1 Qh5+ 22.Kg2 f5 $2 {Defend. Be careful of counter-atacks} 23.e5 f4 24.Qe4 Rf5 $4 {White can easily win this [%draw full,c6,red][%draw full,c7,red][%draw full,a7,red][%draw full,h5,red] [%draw full,d8,red]} ( 24...b4 25.Ne2 Rd5 26.c4 Ra5 $14 ) 25.Kf2 Qh3 $18 {Pieces are too disconnected[%draw full,h3,red] [%draw full,c7,red] [%draw full,c6,red] [%draw full,a7,red] [%draw full,d8,red]} 26.Qxc6 g5 27.Qe6+ Kf8 28.Rxg5 1-0

Edit: SE somehow has errors when flipping it, I suggest not flipping it, or un-flip it at moments where there are arrows/highlighted squares(not much in this analysis)

Clearer PGN for users who can't render the board:

1.e4 e5 2.Nf3 Nc6 3.Bb5 Bc5 4.Bxc6 {?! Minor comment: c3 and O-O are the moves that are studied, this throws away all advantage.} 4...dxc6 5.O-O Bg4 6.d3 Ne7 7.Bg5 f6 8.Be3 Bxe3 9.fxe3 O-O 10.Nc3 Ng6 11.h3 Be6 12.Qe2 Qd7 13.d4 b5 14.b3 {Notice the weaknesses, save them and exploit them later in game. This is an example when you exploit them immediately}
14...Rad8

( 14...b4 15.Na4 a5 16.c4 bxc3 17.Nxc3 )

15.Rad1 exd4{!} 16.exd4 Nf4 17.Qe3 Nxg2 18.Kxg2 Bxh3+ 19.Kh2 Bxf1 20.Rxf1 Qg4{? I suggest you start opening the board and exchanging pawns}

( 20...Qe6 21.Rg1 a5 22.Ne2 Rfe8 23.e5 fxe5 24.Qg5 Qe7 25.dxe5 Qxg5 26.Rxg5 Rd5 )
( 20...Rfe8 21.Rg1 a5 22.Ne2 a4

( 22...Qf7 23.Nf4 a4 24.Rg3 axb3 25.cxb3 Ra8 )

23.bxa4 Ra8 24.axb5 Rxa2 25.bxc6 Qxc6 26.Qb3+ Qe6 )

21.Rg1 Qh5+ 22.Kg2 f5{? Defend. Be careful of counter-atacks} 23.e5 f4 24.Qe4 Rf5 {?? White can easily win this}

( 24...b4 25.Ne2 Rd5 26.c4 Ra5{+=} )

25.Kf2 Qh3{+- Pieces are too disconnected} 26.Qxc6 g5 27.Qe6+ Kf8 28.Rxg5 1-0


Time/PLY to let engine run for opening analysis For critical positions in your opening repertoire:

How many PLY do you recommend to let the engine run on a single move (referring to a roughly equal position, about +0.15-0.2)
How much time does it takes to reach this (obviously depends on various factors, just trying to gauge the reality of other chess players today, non-super users)?

How many PLY do you recommend to let the engine run on a single move

This will depend on many factors such as the actual position, how you use the engine for opening analysis, etc

If the engine gives a decent advantage (let's say +-2 or so), there is usually not much point in having it calculate down to mate. Other than that opening analysis with an engine is tricky and should certainly not be automated. Engines are useful for pointing out tactical mistakes in openings and can be useful in evaluating midgame/endgame positions that result from some opening lines.

However at least currently you cannot expect engines to give you the absolute best line from say move 5 in any opening. In many openings engines give an evaluation of +0.6 or so even though experience shows that positions are perfectly playable for both sides.

Also human interaction is needed to evaluate how playable the position is for a human: e.g. you might have an equal position where you are required to find 10 only moves or so; this is not what you want to get into.

  How long does it take you time-wise to reach this?

Depends on position, computing power and perhaps other factors.


Why is 5. f5 so necessary in the Dzindzi-Indian Opening/Modern Defense: Pterodactyl, Beefeater Variation? I have played a couple of games as black with this line. It is a simple plan: to put pressure on the weak c3 and c4 pawns.

This line is mainly known as the Dzindzi-Indian Opening, according to the comments and this video. It. also called the Modern Defense: Pterodactyl, Beefeater Variation according to chess.com.

[FEN ""]

1. d4 g6 2. c4 Bg7 3. Nc3 c5 4. d5 Bxc3 5. bxc3 f5

I have tried it while playing correspondance, so I have followed the move sugested by databases: 5. f5. This has had good results after quickly playing Qa5, trying to attack the weak pawns along with other minor pieces.

5...f5  347
2018    2403/2426/2709   30.3%  25.6%   44.1%

5...Qa5 22
2017    2359/2306/2586   50%    22.7%   27.3%

5...e5  5
2014    2370/2338/2418   40%       20%     40%

5...d6  1
2010    Steadman vs. Bosboom 0-1

*Chesstempo database for the position

I wonder what the reason is for taking away a tempo to play f5 while the plan is clear, at least as I play it: to profit from the doubled pawns by attacking on the queenside.

Is f5 played to avoid e4?

You don't want a White pawn getting to e5, especially with a friend at f4.  White can let you have a c-pawn if he can achieve such a central dominance.

Also, without f5 it is awkward to develop the Ng8 -- you notice none of the variations you show have Nf6.  But now after f5, Nf6 will grip the e4 square.   Thus White often plays e4 anyway!


How do grandmasters prepare against computer endgames? This question is a sequel to  an earlier one . Just as in the openings, computers dominate endgames.   Endgame tablebases  provide an exhaustive analysis of endgame positions with a small number of chessmen. The undesirable side-effect is that  optimal endgame moves  are often extremely difficult  for an endgame-expert to understand (see the last post by Bill Dubuque in the link above).

  How has this phenomenon changed grandmasters' preparation against computers?

For example, they may not allow a game to continue till the endgame when playing against a computer, unlike a human opponent. Or they may avoid endgames with complex variations.

Note that the endgame allows exhaustive search, and lacks exploitable phenomena like the horizon effect .

As has been stated in the comments GMs don't compete against computers very often. They more often use the computer to help analyse their own games, especially to help find "computer moves" by which I mean obscure unnatural looking moves that they didn't/wouldn't find in the game but which are tactically sound.

The endgame in particular is the part of the game where gameplay methods are well established and it actually comparatively easy to see who has the advantage and how the game will end. In many GM games they resign before I would have even been able to tell we had reached the endgame.

In studying endgames the advice I have seen included in the commentary from a GM that came with Chessmaster 8, and in some books, was to practice recognizing the weapons (ie pin, double check etc) in actual endgame positions, learn the basic rules to help speed calculations in the endgame. These are such things as can the king get into the square defined by the diagonal from the pawns position to the back rank, if he can - and no other pieces can interfere - he can stop the pawn promotion, if not he can't, opposition, etc.


What is black's idea in this puzzle? This is one of Lichess's puzzles, taken from a real game. Black is on the move.
[FEN "1r1q1rk1/5pbp/3pbnp1/1p1Np1B1/1p1nP3/P1N2P2/2P1B1PP/R2Q1RK1 b - - 0 1"]

1... Nxe4 2. Bxd8

The suggested move is Nxe4. However, I don't see how Black gains an advantage after White plays Bxd8.
Correction: The suggested move is Nxd5

You are quite right Nxe4 makes no sense. However Nxd5 does because then Qxd8 ends up losing 4 pieces for a queen:
[fen "1r1q1rk1/5pbp/3pbnp1/1p1Np1B1/1p1nP3/P1N2P2/2P1B1PP/R2Q1RK1 b - - 0 1"]

1...Nxd5 2. Bxd8 Nxc3 3. Qd2 Ncxe2+ 4. Kh1 Rfxd8

However if white doesn't take the queen and instead plays the next most obvious move, taking the knight with the e pawn, white still ends up losing a piece:
[fen "1r1q1rk1/5pbp/3pbnp1/1p1Np1B1/1p1nP3/P1N2P2/2P1B1PP/R2Q1RK1 b - - 0 1"]

1...Nxd5 2. exd5 Qxg5 3. dxe6 bxc3 4. exf7+ Rxf7 5.


What is the best way to interface with Stockfish in a C++ program? I am looking for a way to have my C++ program communicate with Stockfish. An ideal solution would use the compiled version and my program would send commands to the .exe which would return the results. I have looked extensively and have come across suggestions for pipes or the use of the system function but I am not sure how either of those work and if it's possible to have information returned to my C++ program. I am running on Windows. Any suggestions on what method to use and direction on how to apply that method would be greatly appreciated.

The code required for this is platform dependent, so it may be pragmatic to use a third party API to handle inter-process communication for you. Boost provides Boost.Process and Qt provides QtProcess, both of which allow for communication via stdin and stdout.

Otherwise, you will have to directly interact with platform specific APIs, such as CreateProcess on Windows and fork, pipe, etc. on Linux.

Once you are able to communicate with the engine, you just need to follow the UCI Protocol (which is used by Stockfish) to communicate with the engine.