Double Hane

We all know what is a Hane, but what about the double hane?

On the right side we have a sample. A double hane is when you hane twice in a row on the same group. Here you can see how the stone 1 is limits white's growth in this column, so white has to move one line back. Black's 3rd stone pushes back white even more. Depending on the surrounding situation, white can play A, B or C.

A will be played if white is strong nearby and he isn't afraid of leaving cutting points. C will be played if white is very weak in this area and needs to protect the cut at all costs. B is somewhere in between this two positions, it defends the cut, but not as well as C does, and it is less passive than C.

This is a very important technique to apply into your games, but it is a double-edged sword. It can be of great use, pushing white back 2 lines, or even killing him. But it can also lead to a situation with two weak groups floating in the middle of the board because of the cutting points left during the double hane.

On this side we have one clear sample of a good double hane. As you can see, black played 3 making a double hane against the weak white groups.

White now is forced to defend his stones somehow, either A or B are good moves, though defending the cuts directly is not bad either.

If, for some reason, white tried to cut this double hane and black was strong nearby, W would have to face the lost of 1 to 3 stones. Can you read this continuation?

The double hane is best played when if forms a "tiger's mouth", because there is a stone defending both cuts at the same time. Then we don't talk about double hane any more, but about tiger's mouth.

While double hane is so powerful, it is also very dangerous for the one who uses it, so you need to have read all possible continuations and having a counter-plan for them, before doing such a move.

In this situation the double hane is calling for a cut. White will certainly cut at A or B due to his strenght nearby. In fact, even the single hane is a bit of an overplay, because white is able to cut there and black will have left a sacrificed stone which is currently purposeless.

Now let's talk about a specific double hane we see on beginner's games.

Double hane at the border

As we've all been beginners, we've all made this mistake. It is a typical mistake from beginners which we've all learned by being punished after doing it. In fact, I've recently found myself punishing it a few times on my students till they learn not to make the double hane on the border.

If you still don't know what I'm talking about, take a look at the picture on the right. If you think black 3 is a correct move, then you need to read this article. If you think black3 is wrong, you'd probably be able to read the appropriate punishement.

Most beginner's accept this B3 to be a good move, since it blocks white from entering his own territory and makes an atari at the same time. Have I ever talked about how important it is to know when to sacrifice stones? This is a paradigm.

This sequence on the left is the appropiate punishement by white. As you can see, W4 makes an atari, which B defends by killing the stone 2.

White then ataries from black's territory, so if Black just defends that ataried stone, he will lose the 4 stones. Black's only chance is to play at A for making a ko and trying to minimize the damage.

In the end, Black has lost 4 stones + 3 points of territory + whatever white takes from his territory. White's now infiltrated on black's territory and eyespace, so every single stone placed there will mean lots of points lots by black, so W benefits can range from 8 points to killing the whole black group.

Next time black won't make the double hane, and will play at W4, white will play at B5, black will atari and both will defend.