Sunday, September 13, 2015

When not to exchange: Queenstown 2015

The last days of August 2015 were the first time I returned to the chessboard since giving up my pink IC. For those two days at Queenstown CC I stopped being a Private and became a commander instead...

Yelling at pieces that my grandma could run faster than them

The most memorable games of that tourney, however, were not my victories. It were the draws and defeats. For today, I will look at one of those games which I could have won, but ended up drawing due to a strategic blunder: Deciding to trade into an endgame prematurely, and leaving my passed pawn with little support.

Checkerboard 5 vs Opponent
44th Queenstown CC Open Chess Championships 2015

1. c4 Nf6
2. Nc3 g6
3. d4 d5
4. cxd5 Nxd5
5. e4 Nxc3
6. bxc3 c5
7. d5!?

With this the game steers towards very sharp, tactical waters.

7... Bg7
8. Qb3 e6
9. Bb5+! Kf8?!

I was expecting 9... Bd7 10. Bxd7+ Qxd7 11. dxe6 fxe6 12. Nf3 after which Black retains the right to castle but his king is still dangerously exposed.

10. Ba3

Continuing to hit the enemy king.

10... Qc7 (D)

Position after 10... Qc7

Let's do an analysis of this double-edged position. White is more developed, and his Queenside pieces are eyeing down on the Black king which is stuck in the centre. He also has the threat of creating a passed pawn should an exchange occur on d5. However, Black has his own threats. His bishop on the a1-h8 diagonal pins the c3 pawn, and White's Queen is temporarily overloaded looking after both c3 and d5. Here, I decided to consolidate my position first and complete development, since Black's king is stuck and won't be running away any time soon.

11. Rc1 a6
12. Be2

Better than 12. Bc4 b5 13. Be2 giving Black some tempo.

12... exd5?!

I did not consider this move to be best for Black, as it gives White the passed pawn without compensation. I looked at 12... Bh6 13. Rd1 Kg7 14. d6. For a moment it seems Black is in trouble, but after 14... Qc6 15. Bf3 Nd7 16. Ne2 (16. e5?! Qb5 and the e5 square is weak.) 16... Rf8 (D)

Position after 16... Rf8

Black has tucked his king to safety, activated his rook, and blockaded the passed pawn. His only weakness is the trapped light-squared bishop. Play will revolved around d6.

Returning to the main line after 12... exd5:

13. exd5 b5
14. Nf3 Kg8
15. O-O

Now White is clearly better. My plan is simple: Support the advance of the passed pawn, and use it to tie down Black's pieces.

15... Bb7
16. Rfd1 c4
17. Qb4 h5

Black's previous two moves indicate he wants to restrain my light-squared bishop, hindering it from supporting the passed pawn.

18. Qe7

Now I felt a better move was 18. d6 Qd7 19. Qa5 preparing Qc7 exchanging queens to open the file for my rooks. With the pawn on c7 the threat of Rd8+ would have been very dangerous.

18... Qxe7
19. Bxe7 Nd7

A good blockading piece against the passed pawn.

20. d6 Bh6

Position after 20... Bh6

21. Bg5?

Confident of my advantage, I erroneously decided on a series of minor piece exchanges. At first glance, it looks sound: With more pieces off the board, the advantage of the passed pawn will become more apparent. However, that is not so in this position: My passed pawn is far ahead in enemy territory with no friendly pawns to support it. Thus, transitioning into the endgame will deprive it of crticial piece support, making it easier for the opponent to pick it off.


Moreover, note that Black's pawn chain also provides a threatening outpost on d3, which might be important in the endgame. Always consider carefully before you exchange pieces!

Keeping the pieces on the board is better: 21. Rb1 Kg7 22. Ng5 Bc6 (22... f6 23. Ne6+ White is much better here.) 23. Bf3 (This exchange is justifiable as Black's light-squared bishop is a key defender of the position. Without it White's rooks have greater freedom of movement.) Bxf3 24. Nxf3 Rhe8 25. Rd5 (D)

Position after 25. Rd5

The d6 pawn is untouchable, granting White a significant spatial advantage in the endgame.

Returning to the main line after 21. Bg5:

21... Bxg5
22. Nxg5

Now Black's defence is much easier.

22... Kg7
23. Bf3

I looked at 23. Re1 Rhe8 24. a4 (Seeking to demolish the pawn chain and obtain more space for White's bishop.) f6 25. Nf3 bxa4 26. Nd2 Re6 27. Nxc4. Here White has more space for his pieces but Black threatens to double his rooks on the e-file. Notice the d6 pawn is blockaded and in urgent need of piece support.

23... Bxf3
24. Nxf3 Rhe8

Quickly denying White the chance to invade the e-file.

25. Re1 Nc5

Eyeing d7 and d3 at the same time.

26. Rcd1

After 26. Re7 Rxe7 27. dxe7 Re8 28. Re1 Kf6 Black still wins the pawn.

26... Rxe1+
27. Rxe1 Rd8
28. Rd1 Nd3! (D)
1/2-1/2


Occupying the outpost and cutting the d6 pawn from its guardian. Black has managed to equalize and even has a small advantage in the endgame. After a few more mistakes from both sides the game ended in a draw.

...

Lesson learned: Passed pawns need strong support, and always think twice before exchanging pieces!

Sources:
http://www.chessgraphics.net/
http://www.ww2aircraft.net/forum/aviation/gunther-rall-vs-zemkes-wolfpack-9247.html

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