The Ladder (Shicho) in Go: How to Read Whether It Captures

The ladder (shicho) is a technique for capturing a stone by chasing it in a zig-zag, and it is the first essential reading skill in Go. It shows up constantly as the finishing move in capturing problems. But 'chase and you capture' is not guaranteed — you have to read the ladder all the way to the edge of the board first. Here is how to tell a working ladder from a broken one (a ladder breaker).

What a ladder is — chasing with continuous atari

In a ladder you keep the enemy stone in atari (down to one liberty) on every move, alternating the side you atari from so the chase zig-zags. Each time the runner extends, it still has only one liberty, so you atari again from the other side. Block its escape this way and it eventually runs into the edge of the board, or into your own stones, with nowhere left to go — and it is captured. As long as you atari from the correct side each move, the runner is driven into a staircase and caught.

Does it work? Read the path to the edge

The key skill is to read the diagonal path of the ladder all the way to the edge BEFORE you start chasing. If even a single friendly stone of the runner is waiting somewhere on that diagonal, the atari comes off there and the stone escapes. That waiting stone is a ladder breaker (shicho atari). The presence or absence of just one stone flips a ladder between 'captures' and 'fails', so always check the whole path for the opponent's stones (or stones they can reach) before you commit.

The ladder breaker — the danger of chasing a broken ladder

If the ladder is broken, the result is a disaster — not a neutral non-event. The stones you used to chase form a long staircase, each link with very few liberties. The moment the runner connects to the ladder-breaking stone and gains liberties, your chasing chain becomes the weak group and can be captured wholesale. You set out to capture and end up losing far more stones instead. That is why you read a ladder out to the finish BEFORE chasing — running a ladder that does not work is one of the most costly blunders in Go.

The proverb: 'Don't play Go without knowing the ladder'

A ladder's outcome is two-sided and extreme: capture a whole group for a big gain, or get your own chain captured for a big loss. And because the diagonal path runs far across the board, a single distant stone — the ladder breaker — can decide the whole thing. That is why there is an old saying, 'Don't play Go without knowing the ladder.' It is the very first reading technique worth mastering.

How to practice

TsumeDojo's capturing tsumego include ladder-capture problems. Play each atari one move at a time, but picture the whole zig-zag path to the edge before you commit — that is exactly the reading a ladder trains. Once you can see at a glance whether a ladder works, your reading of captures and capturing races speeds up dramatically.