Explanation

If a king has very few escape squares, chess players say that the king is in a mating net. Often the opponent can then catch the king in the mating net by taking away one more escape square or bringing in another attacker with a quiet move.

Sometimes a mating net can be a sacrifice. These can be very tricky to spot, but usually are exceptionally beautiful!

The following diagram illustrates the power of a mating net:

Black has an overwhelming force. White can’t achieve anything with checks; for example, 1.g3+? Kg4 2.Be2+ Kf5 3.Bd3+ Kf6 and the Black king escapes.

However, White can take away the black king's escape squares g4 and h5 with the quiet move 1.Be2! to set up a mating net. White wins because Black can't prevent 2.g3#.

Examples

White can weave a mating net with 1.Bh6. Black has no defence against 2.Qxg7#.

Black's king is in big trouble as it is surrounded by enemy pieces. 1.Rf7+? looks strong, but allows the king to escape with 1...Ke4. However, White can guard the escape square first, and win with the quiet move 1.f3!, after which Black has no defence, for example 1...a1=Q 2.Rf7#.

White can weave a mating net with 1.Bh6!, threatening Qxg7# and also Bxg7#. Black's defence is insufficient.

1...Rxe7 protects against Qxg7#, but not against 2.Bxg7#.
1...Rg8 allows 2.Qxg8#.
And 1...gxh6 opens the diagonal, and allows 2.Qxf6#.