When Chess Players Blunder

An anonymous reader writes: Joe Doliner has done a statistical analysis of mistakes in rated chess games. He used a chess engine called Crafty, which is capable of not only finding mistakes, but quantifying how bad they are. After crunching all the matches on chessgames.com in 2014, which amounted to almost 5 million moves, Crafry found only 67,175 blunders that were equivalent to a 2-pawn deficit or worse. With a pair of graphs, Doliner shows how mistakes decrease as player rating increases, as you'd expect. According to the trendline, gaining 600 rating points roughly halves the number of mistakes a player makes. He made the data and tools available in a public repository for others to dig into.

Comments

Real Chess Players...

[telchine]

Real chess players don't blunder... they make tactical bluffs - Just like professional poker players!

Re:Real Chess Players...

[Kjella]

That's different, in poker you bluff when the probabilities are such that your opponent will lose calling you in the long run. In chess you're creating an objectively worse but more complicated position in the hope that your opponent doesn't have the skills, time and preparation/experience to play it optimally. I rarely do it when we're even, but I've gotten better at doing it when I'm behind.

I remember one game in particular where I'm an officer down (-3) so I sack a few pawns (-3 + -2 = -5) to make his king open for attack, but it managed to set up a Q+R combo that he couldn't see a better defense against than sacrificing his queen for my rook (-5 +9 -5 = -1) and with Q vs exposed king I was able to eat a few more pawns and eventually go on to win the game. I did a computer eval on it and at worst it claimed my position was -8 as after the pawn sacks I'd lose another officer by force.

But I won. If I'd just play passively trying to make my -3 position not worse he'd probably quietly swap pieces one by one until it was a winning advantage. I know I sometimes create such traps against significantly lower rated opponents, I know the threat is possible to defend against but why not see if he recognizes it because if he doesn't it could be an easy win. To genuinely outplay someone where they don't make any significant blunders is certainly possible but easy wins count as much as the hard ones.

Blunder of the Century

[DNS-and-BIND]

Deep Fritz 10 - Kramnik,V (2750). Man vs Machine Bonn, Germany, 27.11.2006. Kramnik played 34...Qe3?? The blunder of the century.

Kramnik played the move 34...Qe3 calmly, stood up, picked up his cup and was about to leave the stage to go to his rest room. At least one audio commentator also noticed nothing, while Fritz operator Mathias Feist kept glancing from the board to the screen and back, hardly able to believe that he had input the correct move. Fritz was displaying mate in one, and when Mathias executed it on the board Kramnik briefly grasped his forehead, took a seat to sign the score sheet and left for the press conference, which he dutifully attended.

In the post match press conference Vladimir Kramnik confirmed that he had not blundered out of exhaustion, and had been calculating very well right to the end. He had no real explanation for the oversight that happened right at the end.

Kramnik in the press conference: "It was actually not only about the last move. I was calculating this line very long in advance, and then recalculating. It was very strange, some kind of blackout. I was feeling well, I was playing well, I think I was pretty much better. I calculated the line many, many times, rechecking myself. I already calculated this line when I played 29...Qa7, and after each move I was recalculating, again, and again, and finally I blundered mate in one. Actually it was the first time that it happened to me, and I cannot really find any explanation. I was not feeling tired, I think I was calculating well during the whole game... It's just very strange, I cannot explain it."

Thus the question that everyone was asking remained unanswered: how can a player of Kramnik's caliber, a world champion who hovers around the Elo 2800 mark, overlook a mate in one move? Naturally there is no logical explanation â" we have to delve into the realm of pattern recognition and the psychology of human perception if we want to understand anything.

The rest of the article turns the board around, looks at it from Kramnik's position, and tries to get into his head to see what he was thinking. Personally, I think it's what I call "sniffing your own butt" when you get so inside yourself, you stop thinking about the rest of the world. You then perform bizarre actions which seem quite reasonable to you. This happens in groups as well. It helps to explain things like how pro-worker governments of the 20th century murdered millions of workers. There's just nobody there to second-guess your thinking, and even if there was, they would be heavily punished for speaking out and contradicting you. This is where crowdsourcing shines.

Unfortunately, Kramnik had somehow not registered the threat generated by the Fritz move 34.Nxf8. The white queen threatens mate in one on h7 (where it is protected by the knight). Black does nothing to neutralise this threat with his move 34...Qe3. And so, after he played it, Kramnik was immediately mated by the computer.

But how could he not have seen the threat after 34.Nxf8. An explanation was proffered by a very experienced chess player and trainer, Alexander Roshal, who is also the editor of the Russian chess magazine "64".

Alexander told us that the mating pattern that occurred during the game, with the white queen protected by a knight on f8 (as in the screen shot above), is extremely rare in chess. It is not one of the patterns that chess grandmasters automatically have in their repertoire. This was confirmed by a GM commentator in Bonn, who after Kramnik's move did not notice that it was a blunder and started discussing White's options â" but not the mate in one.

Re:Blunder of the Century

[MozeeToby]

In one of the Kasparov vs Deep Blue games, Deep Blue made a blunder due to a coding error (it didn't see any viable move but rather than resigning it simply picked a move at random). Kasparov was so convinced that the computer was confused by the play that he thought Deep Blue was looking 20+ moves ahead in the end game, a thought that terrified him. Kasparov won the game, but a lot of people say his confidence was so shaken by that one move that he played significantly differently the rest of the series.

Re:Cause meet Effect.

[gnasher719]

You don't need the worlds best chess engine to find blunders. A really superior chess engine might get 0.1 points advantage in every pair of moves, and after 30 moves you haven't got a chance. But we are talking here about blunders with 2.0 points disadvantage in one move.