However, it is almost inevitable in many sports and games that one-on-one contact takes place and that's when superior technique comes in handy. So let's discuss how you can keep your hands "clean" when things get dirty in go.

Diagram 1: In general, Black should never have played at 1. Attaching black 1 to the white stone seems to hurt White at first, but even if White just extends to 2, the exchange is bad for Black. Count the liberties. White had four liberties at first and now he has five, so he became stronger. On the other hand, Black would have had four liberties had he played a few spaces away, but now he has only three. So Black's attachment only weakened him.

Diagram 2: Not persuaded yet? How about if White plays hane (a diagonal connecting stone) at 2? This definitely weakens the black stone as it has only two liberties left.

Diagram 3: Of course, Black can extend to 3, but White would then defend against the cut by connecting with 4. Again White has gotten a lot stronger from the exchange 1 through 4 as his stones stand by themselves. However, Black's stones need reinforcement at C, for example, as a White move next at A, B, C or D would prove disastrous.

Diagram 4: (White 2 is not shown) That is the reason why you should usually take a more reserved attitude when you attack. To attack the white stone, it is best to leave at least one space between the attacking stone and the target. If White does not respond, black 3 (or A, B, C or D) would be a strong move. The white stone is not dead, but White needs to do something.

Diagram 5: Battles usually erupt when one player attaches his stones to his opponent's stones. Let's take the moves 1 through 3 as an example. This kind of cut happens all the time. This particular cut is called a cross-cut because black not only cuts White's stones, he also cuts his own.

Diagram 6: Usually you should extend the stone you can least afford to lose. Here, you don't want to lose the original stone because it is in the center. The loss of this stone would have a great impact on the whole board while losing the marked stone would only have a local impact. But you do not want to give away the marked stone without putting up a fight. White 4 is the proper move in this case.

In the following problems, try to visualize the correct moves.

Problem 1: We will use the final shape of Diagram 6 to consider some situations you will likely see afterward.

First of all, where should White play after black 1? Try to visualize a few possibilities.

Solution 1: Extending is absolutely necessary. The reason is that it is much more difficult for Black to capture two stones with three liberties than to capture one stone (see Reference 1).

Reference 1: (Black 5 connects where the marked stone was.)
If White does not extend the marked stone and plays at 2, for example, Black will surely capture with 3. White's best move is atari at 4, but Black just connects with 5. White 6 makes a good shape. However, Black can either play at B or capture one stone with C through E. If the ladder at A is good for Black, he will cut there. Whatever happens White is in trouble once his marked stone is captured.

Problem 2: How should White respond to black 3? If Black can capture the entire corner this seems to be a strong move.

Problem 3: Another likely move is black 3 here. Again how should White respond?

Problem 4: Black could also play at 3. Should White save his marked stones or sacrifice them? Find a way to save his stones and determine why this might be a bad strategy. Then, find the best way to sacrifice the stones.

Next week, we will provide the solutions to these problems and do some more basic visualization.

Want to find out more? Come to Ben's Cafe in Takadanobaba,Tokyo (03-3202-2445 or www.benscafe.com), 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.