Renowned Harvard psychologist ...

By Rob Van Zeijst

Renowned Harvard psychologist Daniel Gilbert uses the term "nexting" to describe the process of making a prediction based on information about current events and linking them to past experiences. In his book Stumbling on Happiness, he postulates that the one thing that sets the human race apart from other species is not the ability to produce impressive structures such as the pyramids or the International Space Station, but the capability to imagine. Using the power of imagination is to experience the world not as it is but as it might be.

In his highly entertaining book, Gilbert makes a convincing case that we vastly overestimate our aptitude to predict the future and are saddened unnecessarily because of this.

This can happen in go. We rely on past experiences in working out familiar corner exchanges and middle-game situations and then predict what we think of as perfect endgame tricks. But this does not take into account the strange approach our opponents may adopt. Experience the world of O Meien. O arrived in Japan from Taiwan at the age of 14 and quickly established himself in the Japanese go world with a style that is truly his own. Let's look at a game he played against Satoru Kobayashi (White) in the second round of the NEC Cup.

Diagram 1 (black 29 connects where 20 was captured): Playing elsewhere after 5 is highly unusual. Possibly Black was attracted by the empty corner at 14 after the 7 through 13 sequence. However, making the 15 for 16 exchange, then switching to 17 is even more unusual. White 20, 22 and 24 is a tesuji combination but Black counters with 25, 27 and 29 (connecting where he captured 20). In the hope that white would play at A, so he could follow with black B, Black played at 31. But this was overdoing things. White will resist, but how?

Reference 1: O commented he should have played at 1. White must exchange 2 for 3 now. Probably white A, black B and white C would follow. However, instead of B, Black might want to jump to C, leading to a complicated tussle.

Diagram 2: White's marked stone is not important while Black's are. That is why Black has to answer 32 and 34 with 33 and 35, which assure 36 is sente against the corner. After Black answers with 37 and 39, White can subtly attack the two stones marked with triangles from the other side with 40, which makes eyes as well. Through this shrewd combination, White maneuvers his stones out into the center and more or less connects in the sequence through 72. The 66 for 67 exchange also looks clever as it forces Black to defend at 73. However, now Black is strong, while there are large gaps between White's stones and A around B and C.

Tewari Concept

Reference 2: Here we are going to introduce the difficult concept of tewari. In the game, Black invaded at 1 and then switched elsewhere when White replied at 2. This looks really odd, doesn't it?

Reference 3: The last move in Diagram 2 was the marked white stone. As this is an unfamiliar pattern, how do you evaluate the situation? First, remove a white stone and the black stone to arrive at a pattern you do know.

Reference 4: We now have a standard shimari (corner enclosure), a familiar situation with the stones at A and B removed.

Reference 5: When you think about it, if Black now plays at 1, White is not going to play 2. Instead, he would play at A, B or C (in order of popularity), but never at 2. Therefore, in the game, Black can more or less regard this exchange as kikashi, a forced exchange that is advantageous.

Solution to last
week's problem

Solution 1: White does not have to do anything special; 1 through 5 is enough. This forces Black to defend at 6. If he plays elsewhere, White can play at A, followed by black 6, white B, black C or D (to avoid ko). Then White will jump to E, which kills the Black marked stones.

New Problems

Problem 1: Why is Solution 1 better than this situation?

Problem 2: Look at Reference 5 again. Now think of a situation where the exchange 1 for 2 would be advantageous for White.

Van Zeijst is a four-time European go champion and European representative at the Fujitsu World Championship.