What is tsumego?
Tsumego is the Japanese word for a life-and-death problem: a local position where you must figure out how to make a group live, or kill the opponent's group. A group that can make "two eyes" is alive; one that can't will eventually be captured.
The two-eye rule
An "eye" is an empty point completely surrounded by your own stones. A group with two separate real eyes can never be killed—the opponent can't fill both at once (filling one would put their own stone in self-atari).
So the whole idea of life and death is one sentence: to live, make two eyes; to kill, prevent two eyes. Understand that and you're halfway there.
Why is tsumego the foundation of Go?
- It decides games. Whether a big group lives or dies often settles the whole board.
- It trains reading. Tsumego forces you to calculate sequences precisely—the most concrete skill in Go.
- It's everywhere. Opening, fighting, endgame—life-and-death judgment underlies all of them.
How to practice tsumego effectively
- Start with simple corner problems and build the "two eyes" instinct first.
- Don't skip the ones you miss—wrong answers are exactly your weak spots. Repeat until they click.
- Use spaced repetition: review a problem right before you'd forget it, so memory moves from short-term to long-term.
The classic way is a problem book; a faster way is a structured library with AI explanations that shows how you'd be punished when you slip. Take a free rank test to find your level.