Chess Strategy

We have mentioned zugzwang as one of three methods for winning problem endings (according to GM Nikolai Krogius). Let’s see some examples.

Flohr - Loevenfish

In Bishop vs Knight endings, Bishop can be used for both protecting our own weaknesses and support King’s breach by controlling large number of key squares. The diagram sees pawns on both flanks, which usually favors Bishop. One of the important advantages in this position is that Black King or Knight will be tied for f6 pawn. Straightforward elimination of the weakness with 1. Ke3 f5 2. Kd4 Kd6 3. Bb4 is letting White King in.

1. Ke3 Nf8

Black wants to improve his Knight.

2. Bb4 Nd7 3. Kd4 Nb6

The only chance for Black is active defence - 4. Kc5? Na4. Knight is also heading to the central square d5. White is trying to create permanent pawn weakness on the kingside with…

4. g4 hxg4 5. hxg4 f5

This was tough decision. 5… Nd5 6. Bd2 Kd6 7. f5 and f6 pawn is cemented while 5… g5 6. f5 is hopeless.

6. g5

Already first shapes of the zugzwang. Best square for the Knight is b6, to have Kc5 Na4 or Ba5 Nc4 handy, but he has to move.

6… Nd5 7. Bd2 Kd6

Question: What if 7… Nb6?

8. b3!

Final zugzwang! There is no way to stop White King’s advance now 8… Nb6 9. Bb4 with Ke5 or Kc5 next. Black resigned.

Alekhine - Yates

This position also has Bishop vs Knight and pawns on both flanks, but there are few important differences. Black has passed pawn and all of his pawns are on the squares of same color as Bishop. We will see which factors are of higher relevance. It seems like Black only has to play Bd7-e6 and he will be fine, because White cannot do much while having to watch on the passed pawn.

1. f5!

Right on time before Black activates his Bishop. Now the fight for square f4 is starting.

1… g5! 2. h4! f6! 3. hxg5!

Question: What if 2. f6? And on 3. e6?

3… hxg5 4. Ng1!

Key move. Since Black pieces cannot help protecting g5, While will cause pawn movement and then Knight is heading back to the f4.

4… Bd7

On 4… h4 5. g4! Ba4 6. Ke2! (to stop Bd1) and Ng1-h3-g5 next (Alekhine).

5. f6 Ke8 (5… Kf7 6. Nf3 Kg6 7. Ng5! and passed pawn decides) 6. Nf3 g4 7. Nh4 Be6 8. Ng6 Bf7 9. Nf4 Kd7

Black is holding everything at the moment, but the problem is that his pieces cannot move while Knight is on f4.

10. Ke2!

Zugzwang!

10… a5 11. Ke3 Bg8

Black has to step down. 11… a5 12. a3. White is winning after taking the h5 pawn. Knight will block the passer and King will help pawns’ advance.

12. Nxh5 Bf7 13. Nf4 Bg8 14. Ne2 Be6 15. Kf4 Ke8 16. Kg5 Kf7 17. Nc3 Kf8 18. Kg6 Kg8 19. f7! Kf8 20. Kf6 Bxf7 21. e6 Bh5 22. Nxd5 Be8 23. Nc3 and Black resigned.