The two bishops side by side form a diagonal barrier the black king cannot cross. With the king’s help it is driven into a corner, any corner, and there. Avoid in the final moves.
Moves
No moves yet.
About this endgame
The two bishops can mate a lone king, which a single bishop or knight cannot do with only its king to help. It is the longest of these basic mates: from here, with best play, it takes 17 moves. The bishops work best together, side by side, because they cover two neighbouring diagonals and form a wall the black king cannot get through. The white king pushes from the front while the bishops close the space, first towards the edge and then towards a corner, which is where the happens. What to remember: your king has to join in from the start, and your bishops must stay out of the black king’s reach. Right here there is a check that gives a bishop away. And as in all these endings, watch out for in the final moves.