26 October 2014

Pawn Structure Chess

McDonnell -- La Bourdonnais 1834

Readers may find a note of irony in my reasons for the gap of time between this post and the previous one concerning the first match between Alexander McDonnell (1798-1835) and Louis-Charles Mahé de La Bourdonnais (1795-1840). At the end of June, I started posting analysis of the games in this historic match between the top British player and the champion of France (see "Three Fighting Draws"). I kept up these posts with some regularity through game 22, but then abrubtly stopped in mid-September with three games remaining (see "La Bourdonnais's Infantry").

Teaching history cuts into my time for chess.

This neglect relates to McDonnell's career. At the time of the match McDonnell was secretary to the Committee of West Indian Merchants. This business group was involved in lucrative trans-Atlantic business ventures. I have been studying some of the broader contexts of these ventures.

I teach occasional college history classes for adult students. These classes are brief (six weeks) and quite intense in their focus. The past few weeks, I have been occupied with a new course--relatively new in the worlds of academia and my university and wholly new to me. It is called Atlantic World and covers history of four continents through three centuries. My academic training was focused on North America so I had much to learn preparing for this class.

A central facet of the Atlantic world was the trans-Atlantic slave trade and the production of sugar in the New World. Britain ended its participation in the trans-Atlantic slave trade in 1807 and abolished slavery in 1833. The time of McDonnell's work in West Indian business was a time of dramatic change.

Now that the end of my class draws near, I have more time for study of chess.

McDonnell prevailed in game 23, which was a battle centered on isolated pawns.

De Labourdonnais,Louis Charles Mahe -- McDonnell,Alexander [D00]
London m1 London (23), 1834

1.d4 d5 2.Bf4 c5 3.e3 Nc6 4.Nf3 Bg4 5.Be2 

In 2007, Vladimir Kramnik would play  5.c3.

5...Bxf3

Black creates a minor piece imbalance.

5...e6 was an alternative worth considering.

6.Bxf3 e6

White to move

7.c4

7.0–0 Nf6 8.c3 Be7 9.Nd2 0–0 10.Qb3 Qb6 11.Qxb6 axb6  and White won in 60 moves in Stoletov,G (2246) -- Kovalev,A (1955), Konakovo 2011.

7...Nf6 

From this pawn structure, an isolated queen pawn is common.

8.Nc3 cxd4 9.exd4 dxc4

White has an IQP; Black is a pawn ahead. Black's minor piece exchange deflected White's light-squared bishop from the f1–a6 diagonal.

10.0–0 Be7 11.Bxc6+

White eliminates the minor piece imbalance in order to win back the pawn.

11...bxc6 12.Qa4 0–0 13.Qxc4 

13.Qxc6 does not seem as good. 13...Rc8 14.Qa4 Qb6.

13...Rc8

It seems to me that White's IQP and Black's two isolated pawns should tip the balance slightly in White's favor.

14.a3 Bd6 15.Bg3

15.Bxd6 seems better 15...Qxd6 16.Qc5.
15.Bg5? is worse. 15...Bxh2+ 16.Kxh2 Ng4+ 17.Kg1 Qxg5.

15...Bxg3

White to move

16.fxg3?!

This move increases the mobility of the rook, but also places a burden upon the isolated d-pawn. This move also weakens the e3 square. Looking back from the conclusion of the game makes this move seem the first significant error.

I prefer 16.hxg3. But, even this move offers Black some opportunities. Perhaps White's troubles began on the previous move.

16...Nd5 17.Rae1

Guarding e3

17...Qg5

Increasing pressure on e3.

18.Ne4

Driving the queen back.

18...Qe7 19.b4?!

Another plan might have been 19.Nc5 blockading the isolated c-pawn. White could then place his queenside pawns on b3 and a4. However, Black might then build up pressure on d4. 19...Nb6 20.Qa6 Rfd8 21.Rd1 Rd5 22.Rd2 Rcd8 23.Rfd1 e5! 24.Qe2.

19...a5

Any advantage that White might have realized with fewer isolated pawns will be gone soon.

20.Nc5 axb4 21.axb4 Rb8

White's queen may be compelled to defend White's two isolated pawns, although only one is attacked at present.

White to move

22.Na6?

This move seems to fail tactically.

22.Rb1 Rb5 23.Nd3 Qb7.

22...Rb6 23.b5 Qa3

Black again puts pressure on e3

24.Qc5

24.Ra1 Qe3+ 25.Kh1 cxb5 26.Qc5 b4 and White will need to give up a piece to stop Black's b-pawn.

24...Qxc5 25.Nxc5 Rxb5 

White to move

26.Nd7

26.Rc1 Rd8 27.Rfd1 Ne3 28.Rd3 Nf5 29.Nb3 Rbd5 30.Rxc6 Kf8 31.Rc4 e5 and Black should win.

26...Rc8 27.Ne5 Rb7 28.Rc1 Rbc7 29.Rc5

29.Nd3 c5 30.dxc5.

29...f6 30.Nc4 Kf8

White to move

31.Ra1

La Bourdonnais aims to collect Black's c-pawn. This plan is doomed.

31.Nd6 Rb8 32.Ne4.

31...Ke7 32.Ra6 Nb4 33.Ra4 Rb8! 34.Na5

Black to move

This position is useful for instructing elementary chess students.

34...Nd3

White is losing material due to the checkmate threat. The tactic combines fork and discovery. A line is opened for the rook while the knight forks rook and the king's escape square.

35.Kf1

35.Rc3 Rb1+ and checkmate next move.

35...Nxc5 36.dxc5 Rb5 0–1

McDonnell's play against pawn weaknesses gave him the win. In the next game, McDonnell's experiement with the Evan's Gambit produced "An Opening Disaster".

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