white accepts the trade, instead of blocking in his bishop and night.
15... Nc6xb4
Black happily takes with knight, threatening the c2 square.
16. Be2d1
White must defend the c2 square by taking a defender from d3. However, white cannot quite take advantage of it, yet, because whites rook is now threatening the unprotected black bishop.
16... Rf8e8
Black guards the bishop to put pressure on the c3 pawn.
17. a3
? Fruitless move to force the knight to move because he was already headed for the d3 pawn.
17... Bg4xf3
Black takes advantage of the pinned bishop required to guard the c2 square. if white decides to take the knight he loses the pawn after 18. axb4 Bxd1 19 Raxd1 cxb4.
18. Nd2xf3
White does not hang a rook by taking with the bishop.
18... Nb4xd3
Black is now up a pawn.
19. Re1e3
White tries to take advantage of blacks momentarily trapped knight.
19... c4
Protects knight and makes c5 available for the knight if he should need to flee.
