Snapback in Go — How Uttegaeshi Captures Work | PlayGo.gg

A position where you sacrifice a stone to capture more stones immediately after the capture.

What is a snapback?

A snapback begins when you play a stone into a spot where it has only one liberty — apparently giving the opponent a free capture. But the shape around the sacrifice is the trap: the opponent's adjacent group has only two liberties itself, and one of them is the very point your sacrifice sits on.

The sequence is three beats. You throw in one stone (it has one liberty; the enemy group has two). The opponent captures (the captured point reopens, but they still need it filled). You play back on that point and capture the now-ataried group. The Japanese name uttegaeshi means "strike and return" — you give a stone to take a group, almost always profitably (one for two, three, or more).

When does a snapback work?

Three conditions must hold at once:

- Your sacrifice has exactly one liberty (so the opponent has no choice but to capture or accept it living next move). - The opponent's group, if they capture, has exactly one liberty. - The point that opens after the capture is the same point you can immediately play.

If the opponent's group has three liberties, the recapture gives them an extra liberty and the snapback fails. If your sacrifice has more than one liberty, they can ignore it and the trap melts. Snapbacks live in the cracks of two-liberty shapes.

The danger sign that you might be walking into one: any opponent stone or pair of stones with exactly two liberties where one of those liberties is interior — surrounded by your stones. Before capturing, count the post-capture position. If your group will be in atari after the recapture, the capture is a trap.

Example of a snapback in a game

Where can black play to create a snapback?

Snapbacks are similar in essence to false eyes - you give something up to gain a bigger advantage immediately. This is a common theme in Go!