Nine Men's Morris strategy: build the open mill

What decides a game of Morris

Two things: how many potential mills each side is building, and how many legal moves each side has. Material matters less than either — a player with seven men and no moves is losing to a player with five men and freedom.

1. Take the busy points. The four midpoints of the middle square sit on the crossbars and belong to four lines each; the corner points belong to two.
2. Count mill threats, not men.
3. Mobility wins the middlegame. If your opponent runs out of moves, the game ends.

Level 1 — Basic: the placing phase decides most games

1. Take the crossbar midpoints

The points where the crossbars meet the middle square have four neighbours and sit on more potential mills than anything else. Take them early.

2. Do not chase your first mill

Beginners rush to make a mill in the placing phase and end up with three men in a corner, doing nothing. A mill is worth one enemy man; a good structure is worth the game.

3. Block, but block usefully

When you block an opponent's mill, prefer the blocking point that also builds one of your own. A purely defensive placement is a wasted man.

4. Keep your men connected

Men that cannot reach each other cannot form mills in the moving phase. Spread across two squares with crossbar links, not scattered.

5. Count your opponent's moves

Running an opponent out of legal moves is a win condition, and in the moving phase it is often easier than stripping them down to two men.

Level 2 — Intermediate: the open mill and the squeeze

Build an open mill

The winning structure in Nine Men's Morris is two mills sharing one man, so that a single man shuttles between them and closes a mill every turn. Once it is running and cannot be blocked, the game is over.

Stop theirs before you build yours

An opponent's open mill ends the game, so preventing one takes priority over almost anything else. Watch for the shape forming: two of your opponent's mills-in-waiting sharing a point.

The mobility squeeze

In the moving phase, a man with no free neighbour is a dead man. Strong players advance not to make mills but to take away landing squares, and a player with two or three frozen men usually loses without a single further capture.

Choose what to take

When you close a mill, take the man that:

1. Is about to complete a mill of their own.
2. Gives them mobility — a man on a crossbar point.
3. Would be part of an open mill.

Taking a random man on the edge is usually the worst choice available.

Level 3 — Advanced: structure, tempo and flying endgames

Think in structures, not mills

Strong play in the placing phase is about building shapes with multiple mill threats that cannot all be blocked. The classic is a double-threat placement: one man that completes two different potential mills, forcing your opponent to choose.

Tempo and the forced break

Because a player must move, a well-constructed position can force an opponent to break their own mill or expose a point. Counting who runs out of safe moves first — exactly as in checkers — is the core advanced skill of the moving phase.

The flying endgame

With three men, a player can fly anywhere, which changes everything:

• Three flying men threaten a mill every turn, so a material lead is not enough. You must block the mill each turn and make progress.
• The defender wants open space, the attacker wants to occupy the points that complete the most lines.
• With four men against three flying men, the attacker usually needs a structure that blocks two potential mills at once. Without it, the game is drawn.

Learn what the solution implies

The game is a proven draw, and the practical translation is: do not expect to win from the position, expect to win from an error. Play structures that give your opponent the most chances to go wrong — open-mill threats they must see, mobility squeezes they must count — rather than lines that are objectively best but simple to meet.

Variant awareness

If flying is not used, being reduced in material is close to fatal, and the correct strategy is far more materialistic. Check which rule you are playing before deciding whether a trade is good.

Common mistakes

1. Rushing a mill in the placing phase and ending up with dead men in a corner.
2. Ignoring the crossbar points.
3. Blocking without building.
4. Taking the wrong man after closing a mill.
5. Missing an opponent's open mill until it is running.
6. Counting men instead of moves in the middlegame.

Common questions