Why Do Chess Players Miss The Most Obvious Moves?

We all make mistakes playing chess, proving the old saying "to err is human."'

However, it is one thing to miss a 30-move-deep variation like Fabiano Caruana did in game six of his world championship match. It's a totally different story when you miss something as obvious as a checkmate in one! Speaking of which, here is my worst blunder ever:

So, how could a grandmaster blunder that badly? Was I in a bad form in that tournament? Actually, quite the opposite; it was a good tournament for me. I had qualified for the final matches from my group ahead of many strong GMs, and in the first knock-out match I eliminated GM Etienne Bacrot.

Yes, I had only a couple of minutes on my clock when I played 46...Bh7??, but it is not a good excuse for such a horrendous blunder. The true reason for my blunder is different. This was the last game of our match and I was in a must-win situation. I saw that White is threatening a perpetual check by Nf8-g6-f8, etc. and therefore I played the move that stopped this threat. If this explanation doesn't make sense to you, please try to pass the following test:

So, did you pass the test?

The moral of the story is that we find the moves that we are looking for. I was looking for the move that prevented the perpetual and I was able to find it! I think Vladimir Kramnik made a very similar psychological mistake when he committed an identical blunder:

I bet that Black was mostly thinking about his beautiful pawns on the queenside. "All I need to do is to trade the queens and the game is over!" is what the world champion probably thought, and that's why he played 34...Qe3??

The next game is another example of the same faulty logic.

The game just passed the move 40 and White had plenty of time to find the only move, 43. Kh3. In fact, that move would lead to a forced draw against an opponent whose rating was 200 points lower. This is how GM Tisdall summarized it in New In Chess magazine: "Now, Nick used some deductive reasoning. He should win this game and so perpetual check must be avoided."

As a result, a very strong grandmaster blundered a checkmate!

Finally, let me present you with another blunder from my own game:

Even though I still had about three minutes on my clock, I missed a forced checkmate in three moves! But it is not the funniest part of the story. While I was thinking about my 41st move, GM Lev Psakhis was offering a bet to everyone that Black would not find this checkmate in three moves. You'll be amazed to learn that no one accepted the bet!

The reason is very simple. This was a tiebreak game in a big knock-out tournament in Tilburg (Netherlands) and Black needed only a draw to knock out his opponent. As every experienced player knows, a lone queen cannot checkmate an opponent's king unless the king is surrounded by his own pieces that take away the escape squares. I remembered that when I saw by playing 41...exd4 I would leave my opponent with a lonely queen and my king would have plenty of moves. I didn't look for anything else and just took the bishop!

The lesson here is very simple: When you are thinking about your move, you probably already have some "scenario" of the events that will happen on the board. Based on this scenario you create your plans and goals. But before you execute your move, give the board a fresh look. Did you miss a big gorilla?