recognize chess positions | ChessBase


Veritasium is a science and technology video channel featuring experiments, expert interviews, cool demos, and discussions with the public about all things science. His YouTube channel is very successful. It has between 5 and 90 million views per episode.

This week Veritasium made a very interesting episode about what it takes to become an expert in many different areas of life. One of them is chess. And there is a wonderfully clear description of how the human brain processes chess. Worth watching:

The comparison between experts and laypersons is particularly interesting. Interesting to me as I did similar research almost forty years ago. That’s what I want to share with you in this article. I need to start with some background.

At the end of the 1970s, as a science journalist, I made documentaries for German television. One day I suggested to my boss that we do a report on how computers could play chess. It was very successful and the other German channel asked me to do a similar report. This time we decided to focus on the difference between human and computer thinking. For that we needed topics. So I invited a boy – a very talented boy – to come to Hamburg and take part in a tournament that was going to be held there. His parents agreed to send him alone as I volunteered to put him up in my house and take care of him. He had just turned 15 and I had Lufthansa accompany him when he had to change planes at Düsseldorf Airport. When I picked him up in Hamburg, I looked around for a little boy, but was greeted by a boy who was almost two meters tall.

That was the teenager Nigel Short, with whom I filmed a lot and experimented a lot. He became a family friend and returned to visit maybe 20 times. It was always a lot of fun.

For the second TV documentary, I did quite a bit of research into how the human brain processes chess. I spoke about this with Dutch scientist Adriaan de Groot, the world’s leading expert on the cognitive analysis of chess masters. In the 1940s to 1960s he had conducted tests and described his results in a famous book. Het think van den shaker. Adrian (right) helped me design the experiments we would do for the documentary in Hamburg.

For the TV documentary I used Nigel as a subject and while he stayed at our house I ran a series of experiments on him. He became my most important research object. My experiments would go like this: I would set up a position on the dining table and then call Nigel, who was usually strumming a guitar in the living room. As he approached, I watched his eyes, stopwatch in hand. As soon as they hit the chessboard, I started the clock, and the moment he reacted – said something – I hit round. If it’s “You want me to look at this position?” I’d wait for him to say something position-specific, like “Isn’t the bishop getting a pawn win?” Then I’d stop the clock. I found it took Nigel between five and twenty seconds to solve most of the tactical problems I gave him.

I would also use chess books and show him a position (while covering the solution with my thumb). This image is from a book I still have in which I noted that Nigel found the key, Qh6, in 3.8 seconds.

I also tested his honesty. Occasionally I would take over a position I had shown him a year earlier. He would inevitably say, “Wait a minute, didn’t you show me this before?”

While conducting these experiments, I discovered something quite remarkable. Sometimes the reaction came in less than a second: he would recognize a position once seen almost immediately. I told some researchers in the University of Hamburg’s psychology department about this, and they patiently explained to me that what I was describing could not possibly be true: it was cognitively impossible for a human to identify a chess position with over twenty pieces on the board, in less than one second. They began to analyze – me! They told me that researchers often exaggerated their findings out of sheer enthusiasm for the subject. It was clear that I hadn’t timed Nigel exactly. So I invited her to come to my house and test the guy for herself. This they did, bringing in a chess-trained psychologist and conducting tests in the manner described above. They showed Nigel positions from obscure East German games and challenged him to find winning moves. He did it in seconds, and they spent the afternoon wondering if it was a trick. Given their understanding of how the brain works cognitively, Nigel could not have done what he just did. A group of confused scientists left my house.

I tried to explain to the scientists and the TV audience that Nigel didn’t scan 24 (or more) parts. He saw five or six “super figures” on the board. These are chunks or configurations that make sense. The ten pieces here don’t need to be scanned individually – a single glance will tell the master that this is a ‘fianchettoed bishop in front of a castled king’ and that it came after a 1.d4 opening. The master sees this immediately and draws conclusions just as quickly: the knight defends the d-pawn, the bishop may defend the e4-square, attack b7 and the rook on a8, etc. Very strong chess players have a “vocabulary” of tens of thousands of such chess words, which they recognize and use with virtuosity.

So what is it like for amateur chess players to be faced with the same task? We showed absolute beginners the same positions that Nigel solved in seconds and actually used an optical scanning device to track their eye movements. They actually looked at all the individual parts – and saw nothing. And they could not solve the tactic.

On the other hand, the eyes of World Championship candidate András Adorian generally wandered over the board, lingering on clusters of pieces, but also on empty spaces. In one experiment (pictured above), he said, “It’s very simple!” and proceeded to execute the combination using the a1-rook which he had never looked at directly!

We also gave András random positions with no chess meaning (eg with pawns on the first rank, the white king somewhere in the middle of the opponent’s pieces) to watch for five seconds. Then we asked him to reconstruct the position on a separate board. The result: he had only five or six correct pieces, almost as many as amateurs could remember from meaningful chess positions.

To make all of this clearer to my audience, I conducted the following experiment: I told them to look at the screen, where I would flash 26 letters of the alphabet for five seconds. Then they were asked to write down as many letters as they could remember. Then the following appeared on the screen:

The postman came and delivered

Of course, it took the audience less than five seconds to memorize all 26 letters and their positions. They could do it instantly and flawlessly. The reason was that they memorized words, not individual letters. I then asked her to “complete the sentence.” They immediately came up with useful suggestions: “… a letter”, “… a parcel”, etc. And I praised them as “grand masters” of the language. What they did was similar to what Nigel did on the chess board.

To give the audience a sense of what chess feels like for an amateur, I threw the following string of letters onto the screen for five seconds.

Postimies tuli ja toimitti

This time they could only remember a few letters, like ‘post’ and ‘tuli’, and they certainly couldn’t complete the sentence – which was in Finnish. You were in the position of an amateur chess player who could only remember five or ten pieces and had no chance of finding the winning move.

My experiments with Nigel continue to be instructive and enlightening for me to this day. If I still have your attention, you may wish to hear me discuss the encounters and experiments described above. It starts by telling you how I came up with this type of research and how we presented the results to the German TV audience.


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