18...Bxg5 19.Bxg5 Qd7 20.Nf4±.

The f5-pawn cannot be held.

Black resigned.

White has a bishop that has no good square. After his next move, however, such a square appears, and the black king is seriously weakened:

Other replies are no better.

Black resigned.

Black lands a blow at the most vulnerable point:

A picturesque position. White is completely stalemated.

There is no defence against the transfer of the bishop to f2. White resigned.

White has incautiously moved his rook from f1, where it defended the f2-pawn, and put his dark-squared bishop on a3, where it looks active but does not control any central squares. Black brilliantly exploits these circumstances: