Although go has a history of almost 4,000 years, it continues to evolve. In just about every international tournament, new moves are played in what are considered standard situations. This is because hundreds of young gung-ho players in South Korea and China are unafraid to try new things. However, only a few of these "new" moves end up becoming "standard" moves.

Sacrificing as a strategy

Let's have a look at part of a recently played game between two top pros that starts with a new move and results in sacrifices on both sides to decide the game.

Diagram 1: In this situation, both the black and white marked stones seem doomed. However, they still have a lot of potential and serve a greater purpose. In fact, both players are trying to sacrifice these stones in the most profitable way. It is White's turn--where should he play?

Diagram 2: White 1 is a strong move. Black 2 seems natural, but white 3 is an excellent move that forces Black to exchange 4 for 5 before playing at 6. White 7 and 9 appear to be strange moves, but they make white 11 possible. In turn, Black tries something with 12 and 14 (see Reference 1). However, he then abandons this position to make a rescue attempt with 16, etc. In the end he has to give in and play at 24, which sets up a ko. However, the ko is so one-sided and Black's position so untenable, he eventually has to resign.

Reference 1: After exchanging 1 for 2, Black can cut with 3, and eventually capture three stones with the sequence through 11. However, white 12 sets free the marked white stones, thereby killing four black stones in the corner and three others on the upper edge. At the same time, Black can't cut at A as he would put his own stones in atari. This would be a splendid sacrifice for White.

Reference 2: In the game, White played the marked stone, which Black ignored (to play 24 in Diagram 2 to set up a ko). If he had captured the marked stone, White would play at 2, forcing Black to connect his marked stones with 3. White 4 is a strong move because Black cannot save his marked stones.

Solution to last week's problems

Solution 1A: White 1 sets up a snapback. Of course, Black can capture white 1 by playing at 2, but...

Solution 1B: As you can see, Black has put his own stones in atari. White can play at 3 and capture these stones. Don't confuse this with a ko because the board situation has not been repeated.

Solution 2A: This is a great problem unless you are on the receiving end. White 1 is correct. Black can capture the marked stones with 2.

Solution 2B: However, White throws in at 3. Black can now capture two more stones with 4, but...

Solution 2C: White comes back at 5. It does not matter whether Black plays at A or B. He cannot stop putting his own stones in atari and losing them all on White's next move.

New Problems

Each of these problems employs a throw-in called oi-otoshi.

Problem 1: White needs to make two eyes. How does he do this?

Problem 2: White has one eye. How does he make his second eye?

Problem 3: This problem is more sophisticated. White seems to have no eyes at all. Where should White play to survive?

Hint: He needs to capture the two marked stones in sente and then capture the single marked stone.

Problem 4: White seems to be in trouble. He has only one eye. How can he use a sacrifice and the presence of the marked stone to make an extra eye?

Hint: He should capture at least three stones.

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. You can enjoy free lessons, 11 a.m.-1 p.m.

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