Is dementia reversible? ...
By Rob Van Zeijst
Is dementia reversible? At present, we have no cure for Alzheimer's, but older people in the early stages of senile dementia should consider the advice of internationally renowned neurosurgeon Mitsuo Kaneko. Kaneko is convinced that victims of this devastating condition can stop its progression if they take up go in the early stages of the disease. PET scans reveal atrophy of a large part of the right brain in those suffering from dementia, and go and musical activities invigorate and develop this part of the brain, There are no known cases of Alzheimer's or dementia among go professionals. Research also indicates go stimulates both the left and the right brain hemispheres and reinforces and thickens the connection between them, because it strikes a balance between specific, tactical calculations and a fuzzy overall strategy. In fact, go embodies all aspects of the old adage: Think globally, act locally.
Over the past few weeks, we have discussed the tactical aspects of go in relation to the ko. Now let's now talk about strategy.
Opening game
Although go is an old game, the opening is still undergoing radical changes. For centuries, Japan dominated the go scene and the Japanese way of thinking, its culture and sense of aesthetics have long put their stamp on the game's development. That changed just over a decade ago, when the South Koreans and Chinese started challenging the Japanese status quo and rejuvenated prevailing ideas about openings and standard corner play.
Diagram 1: Until 1992, only a few games between pros featured this opening. However, after 1996, it became very popular, and the opening appears in almost 100 pro games. The reason why it did not become popular before is that it flew in the face of traditional Japanese thinking.
Diagram 2: So what did the Japanese think was more important at the time? In terms of priority, an empty corner was most important, followed by a corner enclosure, or the prevention of an enclosure. Next were extensions along the side, which would usually lead to a battle.
If we look at the upper right corner, the main spots are A through E. A and B are symmetrically placed and, in a sense, "finish" the corner. C is probably the most popular move, while D and E involve special strategies. If the moves are played farther away, the corner opens itself to an invasion. Let's first look at C.
Diagram 3: The idea behind 1 is to close off the corner with a second move, such as 3 (if White plays 2 somewhere else). Alternatives for 3 are A, B, and, to a lesser extent, C.
Diagram 4: However, preventing such an enclosure is important. One way to do that is for white to play at 2, A, B or C.
Solutions to last week's problem
To understand the sequences you need to play out the positions on the board.
Solution 1A (white 22, which connects at A, is not shown): After Black captures a white stone with A, White plays a ko threat at 18, answered by black 19. White then recaptures the ko with 20. The ko threat of black 21 threatens to create another ko. However, white 22 connects the first ko. What happens after black 23? With only three liberties left, White cannot play at A, because of black B. White, therefore, recaptures the ko at C, followed by black D. White's only move is E to take away one of Black's remaining liberties, but then Black recaptures the ko at lower right, putting White's stones in atari and ignoring any ko threat to capture the entire right side.
Solution 1B: The key for White is to do nothing, and wait for his turn to capture the ko. If Black plays at 1, White will capture the ko with 2, putting Black's stones in atari. So Black must capture with 3. However, White will play a ko threat at A. As Black is in atari again, he must capture the ko by playing at B. Granted, White cannot play his next move and must pass again. However, when Black plays at C, White captures the ko (where his stone at 2 was taken earlier), putting Black in atari (remember, White has a stone at A). Black has no ko threats, so White will capture Black's entire group by playing at D. Basically, a similar thing happens when Black when he plays at C.
Solution 1C: Therefore, Black should not do anything either. White will then recapture the ko with 1. In the end, Black only has a ko threat at 2, which is answered by White at A. Next, Black can recapture the ko with B. However, Black cannot really play at C (because White would capture the ko at 1, ignore any ko threat and capture Black's entire group). White can play at 5 to approach the stones in the upper right. Black cannot fill at C, so White must pass. Then white 7 (not shown) recaptures the ko at 1, and since there are no ko threats and Black cannot play at C or D, White can use his next move 9 to further his approach in the upper right. Next, Black 10 recaptures the ko at B, but White takes the crown jewels with 11. In the end, he can approach at C, take the ko and capture all of Black's stones.
As you can see, a ko can become very complicated and confusing, which is why even pros often make mistakes when a multistep or complex ko arises.
Van Zeijst is a four-time European go champion and European representative at the Fujitsu World Championship.