According to Benjamin Franklin ...
By Rob Van Zeijst
According to Benjamin Franklin, the definition of insanity is doing the same thing over and over and expecting different results. Many of us do the same thing every day and hope for the best, or at least we are resigned to whatever result we can get, which often is not too good. The point is that the habits you have formed playing go may not necessarily help you. Indeed, they may hinder your progress. Always think about what you do and why you do it. Don't always play the same moves; try something different.
Let us now look at the game we started last week in the best-of-seven match for the Meijin title between current Meijin Cho U (White) and challenger Satoru Kobayashi. Kobayashi lost the first three games, but has made a comeback by winning the next two.
Diagram 1 (1-44 represent moves 41-84): Black's strategy is to keep White on his toes and never stop fighting. First, he invades White's corner in the lower right in sente before invading at 9. This is important because it is White's largest sphere of influence. See Reference 1 for alternative moves White can make. After 23, Black has more territory. However, note that White can play either at 40 or at A depending on the circumstances. But playing either of these moves too early lets Black off the hook. Instead, White attacks with 24. In the sequence up to 44, White is making territory while Black's group is without eyes. What should Black do? We will see next week.
Reference 1: After black 1 and 3, the exchange 4 for 5 is good for White. However, he does not need to worry too much about the cut of black A, which would be followed by white B and black C, as white D will be sacrificing his marked stone and the stone at 2 in the process. More troublesome for Black would be the exchange black E for white F, after white A. Even if Black jumps to G, White can stop his progress with H. More important, though, is for White to prevent an invasion at I by strengthening his position with 6 through 10. White now has a good game.
Hints for improving your game
Diagram 2: Question every move you make, especially ones played automatically, because they could constitute some kind of aji-keshi, in which you erase potential problems in the opponent's position. As White, are you tempted to force the exchange black A for white B, followed by black C and white D? If so, you are committing aji-keshi, because this would allow both of Black's groups to live unconditionally.
Diagram 3: White 1 is sente and Black needs to reinforce with 2. However, White can play at A to start a ko. Of course, after black B, he will lose points if Black captures one more stone with C. Black earns just four points from winning the ko, but if he loses it, his entire corner, worth 14 points, is lost. This is called a hanami (flower-viewing) ko, because it is very dangerous for one party (Black), who does not profit much if he wins the ko but stands to lose a lot if he loses it.
Solutions to last week's problems
Solution 1A: If Black cuts at 1, and White wants to save his marked stones, he will play at 2. After black 3, any resistance by White is useless, as can be seen.
Solution 1B: When Black cuts at 1, White can save his marked corner stones with 2 and 4. However, Black captures two important center stones.
Solution 1C: Black can do a much better job. Black 1 is the vital point in this case. In the sequence through 5, Black captures the entire corner. There are a few variations, but the main thing is he can do better than in 1A and 1B. It also becomes clear that the exchange of black 2 for white 1 would be disastrous.
Solution 2A: After exchanging 1 for 2, black 3, 5 and 7 are a good combination. With 11, Black forces a ko to free the marked stones. Note that Black has ko threats around 13.
Solution 2B: After 5, White can cut at 6, but black 7 and 9 are a good squeeze. White has to save five stones by connecting at 3.
New Problems
Problem 1: The exchange black A for white B is a case of aji-keshi for Black. How can he capture the marked stones?
Problem 2: If Black blindly responds with A after White plays the marked stone, White will play at B and grab the marked black stones. Where should Black play?
Van Zeijst is a four-time European go champion
and European representative at the Fujitsu World Championship.