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30 votes
Accepted

Why does chess.com consider this promotion a blunder?

50 points sounds huge, but there actually is no meaningful difference between -6.4 and -62 in such an endgame.* 6.4 is more or less "Black has a queen for a bishop (but I haven't found a way to ...
Annatar's user avatar
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29 votes
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Stockfish blunders away a piece

This is not a blunder, expected behaviour from the engine. Everything worked as intended. Try to copy the FEN string out, and you'll know. Although the position looked winning, White didn't have ...
SmallChess's user avatar
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25 votes
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Is this really played by 2200+ players?

In short, after some investigation, I do not believe that white was a 2200 player is the real answer. First, I found it odd that it says he was exactly 2200. This is the only tournament I can find ...
PhishMaster's user avatar
  • 32.6k
25 votes
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Why is g3 a bad move here?

Pawn structure. Allowing the exchange ...Nxf4 gxf4 simply weakens your structure considerably. The pawns on f2, f4 and h2 are disjointed and cannot protect each other anymore. Black can immediately ...
Annatar's user avatar
  • 5,938
23 votes

Why does chess.com consider this promotion a blunder?

This sounds like a bug. Using Lichess's analysis engine, it takes Stockfish 14 less than ten seconds to find a mate in 11 moves. Both 1...Kg3 and 1...g1=Q lead to mate in 11. So there should be no ...
Allure's user avatar
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21 votes
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Improving the observation skill & making less blunders

I will go back to what Artur Yusupov, three-time World Championship Candidate, former top-10 player, and one of the greatest living trainers recommends in the first book of his 10-volume series. In ...
PhishMaster's user avatar
  • 32.6k
21 votes
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Have there been any blunders in resignation?

The official source that people link to when this question comes up is Tim Krabbe's excellent blog post from more than 20 years ago now: The ultimate blunder. He collected every single game in the ...
Andrew's user avatar
  • 15.2k
19 votes

Is this really played by 2200+ players?

White (Rigaud) did not have a Fide rating. Until 1981, the Fide rating floor was 2200, which means that any rated player had at least 2205 and that non-rated players taking part in a Fide-rated event ...
Evargalo's user avatar
  • 16.4k
17 votes

Why is Qf5-c2+ a blunder?

The engine considers Qc2+ a blunder because it's a draw by repetition. (I think the position is probably a draw anyway, but Black could at least try for a win.) The problem is that you have already ...
Stephen's user avatar
  • 1,283
15 votes

Opening positions where declining a gambit is a blunder

Sure, for example the Halloween Gambit. This is not a sound gambit at top levels of play, but if White plays it, Black must accept. The alternatives are even worse. [FEN ""] 1. e4 e5 2. Nf3 ...
Allure's user avatar
  • 27.9k
13 votes

Why is g3 a bad move here?

Other answers have made many good points. But the main reason g3 is a bad move can be reduced to a very simple explanation: The knight on h5 is a very bad piece, it has almost no squares to go to and ...
mainsequence's user avatar
13 votes

Why did Lichess annotate this as a blunder?

Its evaluation drops form +2.3 to +0.0, so it considers it a blunder. Of course this does not match what a human understands as "blunder", but computers are incapable of identifying that. ...
David's user avatar
  • 16.3k
12 votes

What are the worst blunders ever committed in a world championship match (final)?

By far, the biggest blunder in all world championship is absolutely 32.Bb4?? played by Chigorin in the 1892 match. He threw away the win and the match, landed himself to mate in 2. https://en....
SmallChess's user avatar
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11 votes
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Can computer analysis really understand human behavior?

This response will be very critical of OP's attitude to chess analysis, and I realize that it may even come across as somewhat harsh. However, it is assumed below that OP is interested in improving, ...
Scounged's user avatar
  • 7,998
11 votes

I am trying to understand chess moves

14.Nxd4 takes a pawn on d4, and it attacks the bishop on h5. So if black takes back with 14...cxd4, then white has 15.Bxh5, leaving white a pawn up (knights and bishops have roughly the same value). ...
RemcoGerlich's user avatar
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11 votes

Opening positions where declining a gambit is a blunder

Some gambits whose best response is to accept. 1 e4 c5 2 d4 cxd4 4 c3: Sicilian Defence, Smith-Morra Gambit 1 d4 Nf6 2 c4 e5 3 dxe5 Ng4 4 Bf4 Nc6 5 Nf3 Bb4+ 6 Nbd2 Qe7: Budapest Gambit 1 e4 e5 2 Nf3 ...
Rosie F's user avatar
  • 6,425
11 votes

Why is move 12 a blunder for both sides?

The point seems to be that after 12 Nf3? Ne4 Black crashes through on the lightly defended Queenside. For example 13 Qc2 loses directly to axb4 14 cxb4 Bxb4+ because Ra1 is undefended. So 13 Qc1, ...
Noam D. Elkies's user avatar
10 votes

Improving the observation skill & making less blunders

One of the most important things we tell players who are a bit above beginner level is to have a checklist they go through before making each move. It looks like this: checks captures threats ...
Brian Towers's user avatar
  • 98.3k
10 votes
Accepted

How do Stockfish levels work?

Since I could not find any complete explanation, I followed the eternal advice "Use the source, Luke". The Stockfish authors did a great job because their code is easily followable and ...
qwr's user avatar
  • 3,902
9 votes
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Has a "resignation blunder" ever been refused?

Some quick Googling suggests that the rules (or at least some sets of rules) do allow you to refuse a resignation from your opponent This does not reflect the FIDE Laws of Chess. According to Article ...
Brian Towers's user avatar
  • 98.3k
8 votes
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Having knightmares, what to do?

The solution is: play better chess. Train your tactical skills so you can better anticipate the opponent's knight's threats (and also make a better use of your own knights). Avoid creating weak ...
David's user avatar
  • 16.3k
8 votes
Accepted

Why did Lichess annotate this as a blunder?

The "blunder" annotation is derived from server-side analysis using a low engine depth, which is usually inaccurate.
Aaaaaa's user avatar
  • 96
8 votes
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Why is Bxf2+ a blunder in the Traxler Counterattack,?

After 1.e4 e5 2.Nf3 Nc6 3.Bc4 Nf6 4.Ng5, now 4....Bc5 is a mistake by Black. If White goes 5. Nxf7 then following up with 5...Bxf2+ is the best move in that position, so definitely far from a blunder. ...
David's user avatar
  • 16.3k
8 votes
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As a novice, how can I improve at defending my pieces other than what I'm already doing?

It seems like you're having problems with underdeveloped board vision. This is typical for beginners and it takes some time to improve, especially if you're beginning as an adult. But it can ...
Scounged's user avatar
  • 7,998
7 votes

What are the worst blunders ever committed in a world championship match (final)?

As it happens Chessbase ran a story earlier this week featuring "eight egregious elite errors" from past World Championship matches. They are Chigorin-Steinitz (noted by SmallChess), Bronstein-...
Noam D. Elkies's user avatar
7 votes

What are the worst blunders ever committed in a world championship match (final)?

Game six in the second Carlsen-Anand match comes to mind. After 26.Kd2 black can simply take on e5 and after 26...Nxe5 27.Rxg8 he has the intermediate check 27...Nxc4+. Black just remains at least ...
BlindKungFuMaster's user avatar
7 votes

What should the practical meaning of "blunder" be?

The definition of the word is rather subjective, since it depends on how much you value objectivity vs practicality. I think it seems reasonable to take both aspects into account. For example, a move ...
Inertial Ignorance's user avatar
7 votes
Accepted

Why is this move into a simple forced mate annotated dubious and not a blunder?

A blunder is a game-changing move. Nb8 does not change the result of the game which is utterly and completely lost regardless of black's move. Earlier in the game black did blunder when it gave away ...
Brian Towers's user avatar
  • 98.3k
7 votes
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Is it possible for White to win in this rook and knight endgame?

No matter what, White is doomed. Black has much more material and there is no immediate threat to the Black king that White can cook up. The only checks available are futile ones. Additionally, the ...
Rewan Demontay's user avatar
7 votes
Accepted

Why is it a blunder to capture this pawn even if its defender is pinned?

Because you have opposite-colored bishops and it's nearly impossible to win in the endgame. You can, however, take advantage of the weak white king. After 20... Bxc3 the game will most likely continue:...
double-beep's user avatar
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