This exposes Black to further attack by P - R 5 without any compensation for it. If I had to play this position nowadays I would simply play 13...R - K 1. Then after 14 Q × P, Q × Q would follow, and I believe that Black would regain the Pawn. If, instead, White played 14 P × P then B - Kt 5 would give Black an excellent game.

14. P - R 5 B - Kt 2
15. O - O Q - B 2
16. K R - Kt 1 Kt - Q 2

Black's position was bad and perhaps lost in any case, but the text move makes matters worse. As a matter of fact I never saw White's reply B - B 5. It never even passed through my mind that this was threatened. Black's best move would have been 16...K R - Kt 1. If that loses, then any other move would lose as well.

17. B - B 5 K R - B 1

From bad to worse. Kt - B 3 offered the only hope.

18. B × Kt Q × B
19. P - R 6 B - B 3
20. P × P P × P
21. Q × P Q R - Kt 1

The game was lost. One move was as good as another.

22. R × R R × R
23. Kt - K 5 Q - B 4
24. P - K B 4 R - Kt 3
25. Q × R ! Resigns.