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Go Eye Shapes: Which Groups Live and Which Die

⏱ Read ~6 min · Updated July 2026 · Part of: Learn Go

In Go life and death, enclosed shapes have fixed answers. Same three-point space, but straight-three and bent-three's life or death depends on "who plays the vital point first"; square-four lives no matter who plays. Memorize the shapes and most tsumego solve at a glance.

English中文Plain meaning
eye shape眼位the hollow space inside a group
vital point要點（急所）the single point that decides life or death
vital-point shape急所形whoever plays the vital point wins
alive / dead活棋／死棋can / can't make [two eyes](/en/alive-and-dead)

1. Why shape decides life and death

A group needs two eyes to live. Whether it can make two eyes depends almost entirely on how big and what shape the enclosed hollow is. Same size, different shape — life and death can flip.

🧩 Concept: think of the hollow as a room you need to partition into two eyes. Some rooms partition easily (live); some can't be split into two no matter what (dead).

2. Vital-point shapes (the point decides)

These shapes have a vital point — whoever plays it first wins. Your side plays it → live; the opponent plays it → dead.

Shape (enclosed hollow) Where the vital point is Result
Straight-three (3 points in a line) the center point you play center → live; opponent → dead
Bent-three (3 points in an L) the bend's corner same — vital point decides
T-four (4 points in a T) the T's center same
Knife-five (5 points, knife-shaped) middle of the blade same (beginners often misread as alive)
Rabbity-six (6 points, rare) central vital point same

⚠️ Key: these shapes are not unconditionally dead — they're "opponent plays vital point → dead; you play vital point → live." Many guides simplify to "straight-three dies," strictly meaning "if the opponent moves first."

3. Unconditionally alive shapes (live no matter who plays)

These shapes are too big, too complete — the opponent can't kill no matter what.

Shape Status Why
Square-four (2×2 four empty points) always alive wherever the opponent plays, you can make two eyes
Straight-four / bent-four (4 points) usually alive mostly safe (corner has exceptions)
Five-point+ alive too big to kill
Six-point always alive regardless of shape

4. The vital point rule of thumb

Remember one rule: in most shapes, the vital point is in the center.

🎯 At-a-glance: when you see straight-three / bent-three / T-four / knife-five, your first reaction should be "the center point is the vital point." Grab it and you win (live or kill).

5. The 4 most common eye-shape mistakes for beginners

  1. Misjudging vital-point shapes as "unconditionally dead." Straight-three isn't unconditionally dead — if you play center first, you live. When you see a three-point shape, first determine "who moves first," don't reflexively think "dead."
  2. Playing the wrong point. A vital-point shape has exactly one vital point. Playing off-center = didn't grab it = might get killed. Find the right point.
  3. Misjudging square-four as dead. Square-four always lives (you can make two eyes no matter what the opponent does). Beginners see four points and think "vital point decides" — square-four doesn't need a vital point, it's just alive.
  4. Not recognizing knife-five as a vital-point shape. Knife-five looks big (5 points), but it's a vital-point shape (opponent center → dead). Beginners think "big = alive" → get killed.

6. On the 4×4 board

The small board makes shapes small and clear — straight-three, square-four appear everywhere. brainGO's tsumego reward you for instantly judging "this three-point shape, opponent first → dead" or "this square-four, always alive, don't worry."

How to train it

Under pressure, spot the vital point.

👉 Play brainGO — find the vital point

FAQ

Is straight-three a dead shape or alive?

It's a vital-point shape — not unconditionally dead or alive. Your side plays center → live; opponent plays center → dead. Whoever plays the vital point first wins. Many guides simplify to "straight-three dies," strictly meaning "if the opponent moves first."

Why is square-four always alive?

Because the four empty points form a 2×2, and no matter where the opponent plays, you can make two eyes in the remaining space. Square-four doesn't need to fight for a vital point — it's just alive.

Is knife-five dead or alive?

Vital-point shape. Opponent plays the blade center → dead; you play it → alive. Beginners often think "5 points = big = alive," but knife-five is a vital-point shape.

Where is the vital point?

In most vital-point shapes, it's "the center of the shape." Straight-three's middle, bent-three's bend corner, T-four's T center, knife-five's blade middle — all central.

Why is square-four always alive, but straight-three can die?

The key is "can it be killed with a single vital-point move." Square-four (2×2) is symmetric and complete — wherever the opponent plays, you can make two real eyes in the remaining space. There's no point where "one move kills it," so it doesn't need to fight for a vital point. Straight-three has only three points in a line, and after the opponent plays the center, the two remaining points can't form two independent eyes — so the center is the vital point, and whoever plays it first wins. Simply: square-four is "too big and too complete"; straight-three sits "right on the critical edge where it can be killed."

Are eye shapes on the edge/corner the same as in the center?

No — eye shapes on the edge and corner are easier to kill than in the center. The reason is that edge/corner eyes have fewer surrounding diagonal points (corner has 2 diagonals, edge 3, center 4), so the opponent can more easily control them, and eyes made there are more likely to be false eyes. For example, bent-four is usually alive in the center but can become a vital-point shape in the corner (opponent first → dead). So when judging eye-shape life and death, you can't just look at the shape — you must also look at the position: the same shape is more dangerous on the edge/corner and requires extra care.

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