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Connect and Cut in Go: Why Touching Stones Matters

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

Once you can count liberties, the next concept is Go's simplest tactical choice: should my stones connect, or should I split the opponent's stones apart? That's "connect" and "cut" — nearly every local fight is a version of this decision.

English中文Plain meaning
connect連same-color stones touching orthogonally → shared liberties
cut斷／切斷split one enemy group into two
group一群子orthogonally connected stones counted as one unit
diagonal (not connected)對角corner-to-corner ≠ connected

1. Connect: shared liberties, shared fate

Two or more same-color stones connected orthogonally (up/down/left/right) form a group and share liberties — every empty point touching any stone in the group counts once (no double-counting).

🐬 Analogy: hand-holding swimmers share the air around the whole chain. To drown them, the attacker has to cut off the entire group's air at once — far harder than drowning one lone swimmer.

This is why connecting is usually defensive: two connected stones usually have more combined liberties than two lone stones, and can only be captured together.

A connected position (black stones sharing liberties):

These three black stones are orthogonally connected as one group; every empty point around them is a shared liberty. To capture them, the opponent must fill every liberty around the entire group — much harder than capturing three scattered stones.

2. The diagonal trap (beginners must read)

⚠️ Diagonals don't count. Two same-color stones touching only corner-to-corner are not connected — they're two independent groups, each with its own liberties, each capturable on its own.

B .        ← these two B touch diagonally
. B          NOT one group — independent, separate liberties

This is the #1 mistake in the connect concept: assuming diagonal contact means connected. It doesn't. Connection is strictly orthogonal (up/down/left/right). Diagonally-touching stones look "close," but in a fight the opponent can easily cut or capture them one by one.

3. Cut: split the opponent apart

A cut is playing a stone between two enemy groups so they can't connect. Now those two groups are independent — each survives on its own liberties, and you can attack the weaker one.

✂️ Analogy: a wedge driven into a crack in wood. The wood splits into two pieces, and you can deal with each separately.

Cutting is how strong players turn an opponent's solid wall into two fragile groups. Once the opponent's stones aren't connected, you have targets — because the split groups have independent, limited liberties, far easier to capture than when connected.

4. Connect vs cut — one decision, two sides

Every contact between your stones and the opponent's is fundamentally this question:

You want to… So play… Because…
Keep your group alive connect shared liberties are safer
Attack the opponent cut split groups are easier to capture
Defend a weakness connect repair before the opponent cuts
Exploit the opponent's gap cut split them while you can

Rule of thumb: on defense, connect (more liberties, harder to capture); on offense, cut (fewer liberties per group, easier to attack). Whether you should connect or cut in a given position depends on whether you're the attacker or defender.

5. The 4 most common connect/cut mistakes for beginners

  1. Misreading diagonal as connected. Most common. Diagonal isn't a connection — the opponent can split you into two groups with one move. To be connected, stones must touch orthogonally.
  2. Not cutting when you could (missed attack). There's a gap between two enemy groups and you don't play the cutting point, letting them connect later. When you see a cut point, evaluate whether it's worth cutting (usually yes — split groups are easier to attack).
  3. Not connecting when you could (leaving a gap). Your own two groups have a gap, you don't repair it, and the opponent cuts them apart and captures each. On defense, if you see your own cut point, connect first.
  4. Cutting without checking your own cutting stone. When you cut, your cutting stone itself might be in atari. Before cutting, read: is my cutting stone safe? If it gets captured, you've just donated a stone.

6. On the 4×4 board

The small board makes connect and cut brutal and clear: nowhere to run, one cutting move can decide the entire fight. Most 4×4 capture puzzles are, underneath, about preventing being cut or forcing a cut — even when they look like simple captures. brainGO's one-stone variations show how a single connect/cut stone can decide the game.

How to train it

Play a few puzzles and feel the difference between "a connected wall" and "split stones" firsthand.

👉 Play brainGO — connect or cut

FAQ

Do diagonally-touching stones count as one group?

No. "Connected" in Go means orthogonal (up/down/left/right) only — diagonals don't count. Diagonal stones are two independent groups, each with its own liberties; the opponent can easily cut or capture them one by one.

When should I connect and when should I cut?

Rule of thumb: on defense, connect (more liberties, harder to capture); on offense, cut (fewer liberties per group, easier to attack). If you're the attacker, look for cut points; if you're the defender, repair your own cut points.

Why are cut stones easy to capture?

Because after a cut, the two groups are independent — each has fewer liberties than when they were connected (no shared liberties). Groups with fewer liberties are easier to atari and capture.

Can the cutting stone itself be captured?

Yes. When you play between two enemy groups, your cutting stone might be low on liberties or in atari. Before cutting, read: is my cutting stone safe? If not, cutting just donates a stone.

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