The late John W. Gardner, ...
By Rob Van Zeijst
The late John W. Gardner, author and a cabinet member in the administration of U.S. President Lyndon Johnson, said, "We are continually faced with a series of great opportunities brilliantly disguised as insoluble problems." This might be true when it concerns other people, but we hardly think this is a realistic way of looking at our own lives. The more information that is available, the more chaotic a problem seems. The usual approach would be to organize the information to determine what opportunities are available. To be really successful, maybe we should reverse the order and regard the chaotic information itself as the opportunity.
On the go board, the problems themselves are the information. Because every game has a lot of problems, there are many opportunities. They often remain hidden from us, however, because with our level of awareness we just can't seem to see them. These opportunities are inherently difficult to spot. If they weren't, everybody would exploit them. Strong players create a chaotic situation so that opportunities will naturally present themselves. Top pros actually thrive on the pandemonium they create when they are behind in a game. The best way to do this is to start a ko.
Diagram 1: As explained last week, the ko rule states that a full board situation cannot be repeated. So in order to prevent such a repetition, a player must play elsewhere. When Black plays at 1 and captures the stone, for example, White cannot immediately capture the black stone as this would violate the rule for repeating a full board situation. However, if he plays at 2, Black must answer at 3 to keep his corner alive. White can now take back the ko.
Diagram 2: Because of the exchange in the top right, the board position has changed. White can now capture Black's marked stone with 4. Next, it is Black's turn to come up with a move that White has to answer. As you can imagine, this may lead to a prolonged battle of making ko threats, answering, recapturing the ko, etc.
Problem 1: Granted this is an artificial position, but it is good practice material. First, count each territory. White makes the first move. Find a ko he can start. But before playing it, try to determine who will win the ko. Imagine all the threats that need to be answered. Now where should White play?
Solution 1A: If you are close to the dan level, you should be able to determine who will win the ko and the game. First of all, just count the territories. Black has 17 points while White has 15. Therefore, Black is leading by two points. White has to do something to turn the tables. So he must play the ko no matter what. White starts the ko with 1. Since Black takes the ko first, White has to play a ko threat, e.g. at 3. Black must answer with 4.
Solution 1B (black 8 captures the ko where the marked stone is): Unfortunately, we cannot provide a full diagram for each time the ko is taken. For clarity, there are solution diagrams for every other time the ko is taken. White now captures with 5. Black has one ko threat at top right with 6. After 7, Black can recapture the ko with 8. The ko continues after White exchanges 9 for 10.
Solution 1C (black 14 captures the ko): White takes the marked black stone with 11, Black exchanges 12 for 13 and takes the ko with 14. White now makes a ko threat with 15. Black must capture the stone with 16.
Solution 1D (black 20 captures the ko): The number of possible ko threats is decreasing. After White takes the ko with 17, Black plays his last ko threat at 18. White must answer with 19 and Black recaptures the ko with 20; 21 is White's last ko threat. Black answers with 22.
Solution 1E: When White captures the ko with 23, Black has no threats left. Regardless of Black's next move (e.g., at A), White captures three stones with 25 to kill Black's group in the top left. Therefore, he will win the ko and the game. This is an example of a successful launch of a ko battle.
Solutions to last week's problem
Solution 1: As you can see, having sufficient ko threats is important. So when White captures the ko in problem A with the marked stone, Black's best option is probably to eliminate his biggest ko threat. Next, if White fills in a liberty with 2, Black captures the ko with 3. There is no guarantee he will win the ko, but eliminating a ko threat and being the first to capture the ko gives him the edge.
In problem B, Black should play at 1. The only way White can fight back is by answering with 2. However, Black is the first to capture the ko with 3. In theory, he could have eliminated all ko threats before starting this ko.
Solution 1F: Therefore, according to the Japanese rules, this formation is dead. However, in the Chinese rules, this situation is undecided and Black must prove he can capture it and win the ko.
Van Zeijst is a four-time European go champion and European representative at the Fujitsu World Championship.