Minesweeper

Minesweeper Corner Patterns — Forced Deductions at the Edge

5 min read  ·  Burmly

Corner and edge cells in Minesweeper have fewer unknown neighbors than interior cells. A number in a corner has at most three unknown neighbors; on an edge, at most five. This constraint makes deductions tighter and often forces definitive conclusions faster than interior patterns.

The true corner — 1 in the corner

A 1 placed directly in the corner of the board (or touching the actual corner cell) has at most three neighbors total. If two of them are already cleared or flagged, the 1 may have very few candidates left.

Top-left corner: [?][?][ ] ← top row (cleared cell at right) [?][1][ ] ← 1 is here [ ][ ][ ] ← all cleared below

The 1 has neighbors: top-left (?), top (?), and left (?). Exactly one of those three is a mine. No deduction yet — but if any one of them gets flagged by another number, the remaining two are immediately safe.

Corner 1 with one unknown neighbor

If a 1 in or near the corner has only one remaining unknown neighbor, that neighbor is the mine. Click all other unknowns adjacent to the 1 safely.

# = cleared, ? = unknown, F = flagged [?][#][#] [#][1][#] [#][#][#] The 1 has only one unknown neighbor: top-left corner. → That cell is a mine. Flag it.

Edge 1-1 pattern

Two 1s in a row along an edge, with the same unknown cells on the open side.

Edge of board (top row is boundary): [?][?][?] ← unknown [1][1][#] ← two 1s, rightmost cleared Left 1 neighbors: A and B (the two unknowns above it) Right 1 neighbors: B and C (but C is cleared, so just B) Right 1 needs 1 mine in {B} → B is a mine Left 1 needs 1 mine in {A, B} → B already fills it → A is safe

The 1-2 edge pattern

A 1 and a 2 along an edge sharing unknown cells is one of the most common edge deductions.

[?][?][?] [1][2][#] Label unknowns A, B, C left to right. 1 needs 1 mine in {A, B} 2 needs 2 mines in {A, B, C} From the 1: exactly 1 mine in {A, B} From the 2: 2 mines in {A, B, C} = 1 from {A,B} + C must be a mine → C is a mine. A and B have exactly one mine between them (unknown which).

Why corners matter strategically

When you open a new game, clicking near the center gives you the most information — interior cells reveal many neighbors. But when the solve stalls, edge and corner numbers often provide the cleanest forced deductions because their constrained neighbor count leaves fewer variables to resolve.

Opening move: Never start in a corner. The corner has only 3 neighbors — the worst possible first click for information density. Click near the center.

Apply these patterns in a live game

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