The naive investor might believe ...

By Rob Van Zeijst

The naive investor might believe there is a 50 percent chance of making money on the stock market as it will either go up or down. Why is it then that only 10 percent of active traders make money? This might be easier to understand if we apply the logic of go. We could say that each move may be good or bad, meaning that there is a 50 percent chance a player will be lucky and an equal chance that he will be unlucky. However, in a go game there is a huge difference between skilled and unskilled players, even though, measured over the span of one move, both may make a mistake, even the same one.

Sometimes you have an opportunity to play a move that changes the landscape of the board. This occurred in the game in which Yuta Iyama (white) beat Huang Yizhong in the Nakano Cup, a tournament open to players below the age of 20. We started the game last week. Let's see what happened.

Diagram 1 (1 and 2 represent moves 69 and 70): Black 1 was the final move last week. The question we asked was where should White play? White 2 is a move that deserves attention as it combines a number of important functions. The stone strengthens the marked white group, reduces the influence of the marked black stones, aims at an invasion on the right, and plans to help the stone marked with an X at a later stage. Now imagine if White played at A while Black played at B. Black would be able to expand his territory on the right while attacking White's marked stones. Note that black B and C are sente as either of these moves threaten the sequence of black E, white F and black G, leading to the capture of some white stones.

Diagram 2 (1-32 represent moves 69-100): After white 2, Black has to attack. He does this with 3 and 5. White must not play at 13, because the sequence black A, white B and black 6 would be terrible for White. It is important to resist with 6 and 8 even if this allows Black to cut with 11 and 13. A battle now erupts centering on White's group that is cut off on the right. The problem for White is to stay alive while not giving Black too much territory on the right. To that end, how should White proceed after 33? We will continue this game and find out the answer next week.

Hints for improving your game

Diagram 3: This formation appeared last week. Even without the marked stones, both Black and White cut and are cut at the same time. The marked stones emphasize the cut and strengthen the cutting stone in the most efficient way.

Diagram 4: When the black stones have this formation, they apply less pressure on the stones marked with X, while applying more pressure on the white stone marked with the triangle. White 1 gives White's stones bad shape. In general, it is better to push at A or B. Now look at Diagram 2 again. Black cuts with 11 and 13, then reinforces with 15. You can now see how 11, 15 and the marked black stone form an inefficient shape, similar to 1 in Diagram 4. The similarity in the shapes may help you understand more about cutting stones and how efficiently they work.

Solution to last week's problem

Solution 1: Diagrams 1 and 2 provide the answers to last week's Problem 1.

Solution 2: Instead of A, black 1 is correct. White's best counter is 2 followed by black 3, white 4 and black 5, leading to a ko. With 6, White takes the ko first, which is a big advantage. However, this is Black's best line of play.

Solution 3A: Black 1 is bad because White can now kill with the combination of 2 and 4. White 6 is good. When Black plays at 7, white 8 may come as a surprise. It takes away Black's second eye. Black cannot play at A (as White will capture with B), but if he captures at B instead, white A kills him anyway. In other words, Black is dead.

Solution 3B: On the other hand, if Black plays at 5 after 4, again white 6 is the key. If Black plays at A, White would respond with B, and vice versa. Either way, Black is dead.

New Problems

Problem 1: Where should Black play to kill White's group?

Problem 2: Black 1 is a blunder. Where should White play next?

Problem 3: Black to play. How can he kill White?

(In last week's Magic of Go column, diagrams for Solution 3 and Reference 3 were captioned reversedly.)

Want to find out more? Come to Ben's Cafe (03-3202-2445, www.benscafe.com) in Takadanobaba, Tokyo, where the English-speaking go community congregates every Sunday, 11 a.m.-1 p.m.

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