The two bishops mate is an endgame technique that forces checkmate using two bishops in coordination with the king, without the support of additional active pieces.
This endgame is theoretically winning but requires precise and methodical play. The two bishops, controlling diagonals of opposite colours, work together with the king to gradually restrict the opposing king, pushing it toward the edge and then into a corner. A crucial point: the final checkmate can only be delivered in a corner whose colour is controlled by one of the bishops — if the enemy king flees to the wrong-coloured corner, it must be manoeuvred to a suitable one. The technique relies on consistently tightening the available space and may require around thirty moves.
In practice, position the two bishops on parallel diagonals to form a 'wall' that drives the enemy king back, while your own king advances to assist in the encirclement. Beware of stalemate: it is the most common pitfall in this endgame, particularly when the enemy king is trapped in a corner with very few squares available.