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Connections and shapes · Lesson 11

Tiger’s mouth: can an empty point protect a connection?

Three stones around an empty point form a tiger’s mouth. It can protect a connection: an opponent entering the mouth has just one liberty and may be captured immediately.

From the initial diagram, White can enter E5, then Black at E6 captures it. A legal move and a useful move are different things. A tiger’s mouth is not safe in every position either.

If the stones forming the tiger’s mouth are already in atari, or nearby white stones provide support, the result may change. Threatening a cutting point is a peep or probe; inserting directly into a one-space jump is a wedge. Always include the liberties in the following sequence.

Tiger’s mouth

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Black D5, E4 and F5 make a tiger’s mouth around E5, opening toward E6.

White plays inside

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White can play E5 but has only E6 as a liberty. It is legal, yet may be captured immediately.

Black captures

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Black E6 removes White E5’s last liberty and captures it. This conclusion applies to the shown position without other supporting stones.

Original lessons by Yiban ·