Fun with Queens

It seems like for every endgame aficionado there must be two dozen opening theory nuts. It's a strange but enduring fact that openings incite the imagination in a way that endgames simply do not, and yet, many of the most mysterious and magical chess positions arise in the endgame, and the silicon brains often struggle to assess them as much as we do (depending on processor depth, of course).



Here's a simple endgame concept that I particularly enjoy. Note, whilst rook endgames are mystifyingly complex, pawn endgames always seem like fun to me, even when I can hardly grasp what's going on.



White to move and win.

The most natural continuation is obviously 1. g6, racing to get the queen. It transpires, however, that this does not win.

1... a4+ 2. Kxa4 b3 3. Kxb3 h3 4. g7 h2



Obviously, 5. g8=Q is stalemate, so white plays

5. Kc2 Kg2 6. g8Q+ Kf2

But here, white's king is too far away to win the rook-pawn ending:



7. Qf7+ Kg2
8. Qg6+ Kf2
9. Qf5+ Kg2
10. Qg4+ Kf2
11. Qd1+ Kg2



And white cannot make progress.

For those who are unfamiliar with this endgame theme, the key position here would arise if the white king were one square closer, eg.



Now, the winning move would be:

12. Ke3! h1Q
13. Qf3+ Kg1
14. Qf2#

So, returning to our original position, what does white do?



Another possibility would be:

1. g6 a4+
2. Ka2 b3+
3. Ka3 b2
4. Kxb2 a3+
5. Ka2 h3



This variation is even worse than the previous one!

No, white must play the ridiculous:

1. Ka4

Now, let's first establish the trouble that black gets into by leaving his queenside pawns on the board:

1. ... h3
2. g6 h2
3. g7 Kg2
4. g8Q+ Kf2



5. Qf7+ Kg2
6. Qg6+ Kf2
7. Qf5+ Kg2
8. Qg4+ Kf2
9. Qh3 Kg1
10. Qg3+ Kh1
11. Qf2



And here the presence of the b-pawn kills black, as mate follows on f1.

So, after 1. Ka4, black must play

1. ... b3



2. Kxb3 a4+

And this here comes the key idea in this endgame!

3. Ka3!

White traps the a-pawn, reserving forced tempos for black so that white may force the mate that we saw in the previous variation, eg.

3. ... b3
4. g6 h2
5. g7 Kg2
6. g8Q+ Kf2



7. Qd5 Kg1
8. Qd1+ Kg2
9. Qg4+ Kf2
10. Qh3 Kg1
11. Qg3 Kh1



And here we have the key resource:

12. Kb4, forcing 12. ... a3
13. Qf2 a2
14. Qf1#

What's amazing about an endgame like this is on a sort of quantum level, it visually demonstrates the effect of the dimension of time. White has everything in hand, but needs black to have a tempo in order to be able to maintain orchestrate the final attack.