[Event "BUCA v. West German Students"]
[Site "Erlangen FRG"]
[Date "1968.??.??"]
[EventDate "?"]
[Round "?"]
[Result "1-0"]
[White "Raymond Keene"]
[Black "Georg Pollak"]
[ECO "A04"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "81"]

1. Nf3 { Notes by Raymond Keene. } Nf6 2. g3 d5 3. Bg2 g6
4. c4 c6 5. b3 Bg7 6. Bb2 O-O 7. O-O Re8 {Black wished to
provoke White into playing d2-d4, but since I was intending
this in any case it would have been better to continue with
7...a5 or 7...Bg4.} 8. d4 Ne4 {If White is allowed to play
e2-e4 he will obtain a marked central preponderance, thus the
immediate struggle turns around occupation of this square.}
9. Nbd2 Bf5 10. Nh4 Nxd2 11. Qxd2 Be6 12. Rac1 {12 e4 dxc4 13
d5 is not convincing for White. After the text e4 cannot be
prevented by rational means, but Black will always have
counter-chances against White's slightly weakened d-pawn.}
12...Nd7 13. e4 dxe4 14. Bxe4 Qb6 {Here I had expected
14...Bh3 15 Rfd1 Bg4 16 Bf3! with a grip on the centre.}
15. Rcd1 Rad8 16. Qe2 Nf6 17. Bg2 a5 {A logical plan to attack
White's queen's wing, but more active is 17...Qa6! and if 18
Ba1 b5! fighting for control of d5.} 18. Rfe1 Qa6 19. Qc2 Qa7
{Intensifying the pressure against White's d-pawn, but in view
of the game continuation 19...Bg4 would have been more
prudent, especially since Black was now beginning to run short
of time.} 20. Rxe6 {!? I spent half an hour considering this
sacrifice before playing it. I felt that a slower method, such
as 20 h3, followed by a central regrouping, would allow Black
to untangle his pieces and possibly introduce simplification
along the a-file. 20 Rxe6!? is a primarily strategic offer
based on the weakness of Black's pawns and the isolated
position of his queen.} 20...fxe6 21. Re1 {Underlining the
strategic nature of the exchange sacrifice. A more violent,
tactical, course, such as 21 Bh3 fails to 21...e5!, e.g. 22
dxe5 Rxd1+ 23 Qxd1 Ne4, or 22 Be6+ Kh8 23 Nf3 exd4 24 Ng5 Rf8
with good chances for Black.} 21...Nd7 {Black has a difficult
choice: if he returns the exchange with 21...Rxd4 22 Bxd4 Qxd4
then 23 Nf3! leaves White with a plus; or if he attempts to
open files for his rooks with 21...c5 then 22 d5!! exd5 23
cxd5 Nxd5 24 Nxg6! Bxb2 25 Bxd5+ Rxd5 26 Nxe7+ Rxe7 27 Rxe7
Bg7 28 Qe2! +/-. However, there is a very complicated draw
concealed in the position by means of 23...b5. Now White must
act quickly, before Black unravels hence 24 Nxg6! hxg6 25 Qxg6
Rf8 26 Re5 Qd7 27 Rg5 Rf7 28 h4. At first, I thought this was
an easy win for White but the Fritz program proved that Black
can hang on with the following amazing piece of tactics:
28...Kf8 29 h5 Nxh5 30 Bh3!! Qxh3 31 Rxh5 Rd6! 32 Qg5 Qd7 33
Bxg7+ Rxg7 34 Rh8+ when White is obliged to give perpetual
check. Shying away from these complications, Black relies
instead on solid defensive play.} 22. Nf3 Nf8 23. c5 {Further
shutting out Black's queen and preparing to transfer the
bishop to c4.} 23...Bf6 24. Ne5 Qb8 {Should Black play
24...Bxe5 then 25 Rxe5 followed by Qe2 and Bh3 would cause
severe embarrassment.} 25. Bf1 Qc7 26. Bc4 26...Rd5 {This
attempt to relieve the pressure by returning the exchange
fails completely since Black is left with weak a- and e-pawns
and a porous king position. Correct is 26...b6 27 cxb6 Qxb6 28
Qe2! (not 28 Nxc6 Qxc6 29 Bxe6+ since Black collects too much
material for the queen) followed by Qg4, when Black still
retains some defensive possibilities despite White's
aggressive set-up and sounder pawn structure.} 27. Bxd5 exd5
28. Nf3 Qd7 29. Qe2 Qf5 30. Bc3 Ra8 31. a4 {! Fixing one
weakness for ever.} 31...Qd7 32. Bd2 Qf5 33. Bc3 Qg4 34. Kg2
Qc8 35. Ne5 {Black cannot capture on e5 since his dark squares
would become hopelessly weakened, but now White threatens 36
Ng4.} 35...h5 36. h3 Kg7 37. Bd2 Nd7 {This looks bad, but
improvements are hard to find.} 38. Qe3 Bxe5 39. Qh6+ Kg8 {Or
39...Kf7 40 dxe5 Nf8 41 e6+ Nxe6 42 Qh7+ Ng7 43 Rxe7+ Kxe7 44
Qxg7+ and wins.} 40. Qxg6+ Bg7 41. Rxe7 {He loses three to
four pawns.} 1-0