[Event "Cornwall v Somerset"] [Site "?"] [Date "2013.11.30"] [Round "6"] [White "Lloyd Retallick"] [Black "Chris Purry"] [Result "1/2-1/2"] [ECO "D34"] [PlyCount "75"] [EventDate "2013.??.??"] {Lloyd Retallick has supplied detailed notes from his deep analysis of this complex game from the 2013 Somerset match} 1. d4 d5 2. c4 e6 3. Nc3 c5 4. cxd5 exd5 5. Nf3 Be6 {A Chess opening principle is to favour developing short range knights before long range bishops – other things being equal – to preserve flexibility. Here the pawn on d5 doesn't need defending and it's too early to commit the light-squared bishop to e6.} 6. g3 Nc6 7. Bg2 Be7 8. O-O Nf6 9. Be3 (9. Bg5 {would likely transpose into main line theory. On e3 the bishop creates tension before black has castled.}) 9... O-O 10. dxc5 Qa5 11. a3 Ng4 { Since the pawn is poisoned black goes for complications.} 12. Bd4 (12. b4 Nxe3 13. Qd3 Qd8 14. fxe3 {gives white an extra pawn and a better position – the doubled pawn can be readily traded at an opportune moment and white's pieces are well placed. Any attempt to open the Queenside by either a5 or b6 can be repelled by b5.}) 12... Nxd4 13. Nxd4 Qxc5 14. Rc1 (14. e3 {would consolidate a small but thematic advantage, aiming for long term pressure against the isolated QP. Here the retreat Nf6 plays into that plan, whereas Ne5 attempts to complicate.}) 14... Bg5 15. Nxd5 {Taking back the initiative and leaving residual pressure against the black queenside at the cost of the exchange.} ( 15. e3 {fails to} Nxe3 16. fxe3 Bxe3+ 17. Kh1 Qxd4) (15. Nxe6 fxe6 {doesn't help} 16. e3 Nxe3 17. fxe3 Qxe3+ 18. Kh1 Rxf1+ 19. Qxf1 Qxc1) (15. f4 {is no better} Bf6 16. Ncb5 Qb6) (15. Ra1 {has no immediate response} Ne3 (15... Rae8 {is one way for black to apply unpleasant pressure.}) 16. Nxe6) ({What's wrong with} 15. Rc2 {keeping the rook on the c-file? I remember rejecting it during the game, but have forgotten my reasoning. Initially during my post-game analysis I concluded it failed to a knight fork from e3, e.g.} Be3 (15... Nxf2 {is an alternative way for black to try and exploit the dark square weaknesses, but after} 16. Rxf2 Be3 17. Nxd5 Bxf2+ 18. Kxf2 {white is fine}) 16. fxe3 (16. Nxd5 Qxd4 17. Nxe3) 16... Nxe3 17. Nxd5 (17. Qd3 Nxc2) 17... Nxc2 {winning for black. Thus, subject to computer analysis showing better lines, 15. Rc2 was the best alternative. What this emphasises though is that in (human) practice we are continually relying on imperfect analysis and, under time pressure, our games are typically littered with inaccuracies.}) 15... Bxc1 16. Nb3 Qb5 17. Nxc1 Qxb2 18. Qa4 Bxd5 {After this sequence we are left with an extraordinary position, where I count no fewer than 10 candidate moves for black:} (18... a6) (18... a5) (18... f5) (18... h5) (18... Kh8) (18... Nf6) (18... Nxf2) (18... Qe5) (18... b5 {Playing for a middlegame showdown} 19. Qa6 Rad8 20. Nf4 Bc4 { White is invited to nab the Pa7 but will struggle to survive in the centre.}) { Given that both players have used considerable time getting to this point, simplification is a practical choice for black.} 19. Bxd5 Nf6 20. Bf3 a6 { Since the Queen is about to be evicted from b2 anyway, bringing forward Qb6 is sensible here.} 21. Nd3 Qb6 22. Qc2 Rac8 23. Qa2 Rc7 24. a4 Qd6 25. a5 { White can claim a small victory here, maintaining pressure on the queenside pawns and thereby making black's task a little harder.} Rd8 26. Rd1 Qe7 { A little 'shadow boxing' of no great consequence.} 27. Rb1 Ne4 $6 {Black initiates a series of Knight moves here, in line with his quest for a simplified endgame. The question mark is not so much for this move, rather the whole sequence, omitting a prophylactic kingside pawn move to rid black of any back rank mate threats.} 28. Rb6 Nc3 29. Qd2 Na4 (29... Nb5 {was the move I feared during the game.}) 30. Rb1 Nc5 31. Qb4 Nxd3 32. Qxe7 Rxe7 33. exd3 Rxd3 $2 {The game continuation reveals this pawn to be poisoned. Instead} (33... Rdd7 {temporarily holds on to the Queenside pawns, e.g.} 34. Kg2 g6 35. Rb6 Rxd3 36. Bxb7 Ra3 37. Bxa6 Rxa5) 34. Bxb7 Red7 {The a6 pawn can't be defended because of the back rank mate threat.} 35. Bxa6 Rd1+ 36. Rxd1 Rxd1+ 37. Bf1 { That's the point – the bishop retreat simulanesouly blocks the check and frees the a6 square as a safe haven for the pawn.} Kf8 38. a6 {Although black could carry on risk free for a while if he chose to, the position with the extra pawn is an easy draw. Without that pawn (to address the question posed above) it should be winning. In his book 'Endgame Preparation' John Speelman shows that with pawns on f2-g3-h4 against pawns on f7-g6-h5 black, with the Rook, has an easy win if white's bishop is of the same colour as his pawns. With the opposite coloured bishop, as here, he reckons after several pages of analysis that black is probably winning with best play, but not conclusively so!} 1/2-1/2