Minesweeper Pairs: The 1-2 Pattern

The pair technique says: when two numbers share some hidden squares, but each also has squares of its own, work out how many mines the shared squares can hold. That’s limited by both numbers, and the limit often settles the squares only one of them touches. Its best-known form is the 1-2 pattern.

This is the fourth of the Minesweeper techniques.

The rule

1. Find two numbers whose hidden squares overlap, and take the flags off both.
2. The shared squares can hold no more mines than the smaller need, and no more than there are shared squares.
3. If the bigger number needs more than that, the rest are on its own squares: if that fills them, they’re mines. And if the smaller number’s mine has to be in the shared squares, its own squares are safe.

In a real game

On the Expert board every technique page follows, the first pair comes at step 30. A 3 with one flag needs two more mines, and the 1 beside it needs one. They share two hidden squares, which can hold at most one mine, because of the 1. So the 3’s own square is its other mine, and the 1’s own square is safe.

How often you’ll need it

On 4 of 200 Beginner boards, 18 Intermediate and 114 Expert. On Beginner it’s rare, but on Expert it comes up on more than half the boards. On the Expert board here it’s needed 3 times.