Tuesday, May 24, 2011

An update on the refutation of the refutation !?

Last week, I covered Euwe's refutation of the Blackmar Diemer. The Dutch worldchampion played 6...c5 ( diagram ) after the opening moves 1.d4 d5 2.e4 exd4 3.Nc3 Nf6 4.f3 exf3 5.Nxf3 e6 6.Bg5 and believed it was the refutation of the Blackmar Diemer. But Diemer quickly replied with 7.Bxf6 and the continuation 7...Qxf6 8.Bb5+ Bd7 9.00 was believed to be much better for white.

For example, Scheerer gives only the short text "6...c5 is also premature as 7.Bxf6! Qxf6 8.Bb5+ Bd7 9.0-0 sees the queen in the firing line again...". Now you might know by now that I am not an enthusiast on this book - but here the auther seems to loose it completely as 9...cxd4 brings the defender again one pawn closer to a  winning endgame, realising that white has no crushing win after both 10.Ne4 Qe7 or 10.Nxd4 Qe5 (=).

So what continuation is best ? I believe I found the answer, but white certainly does not have a crushing victory in sight, but following line offers white best chances for a win : 6...c5 7.Bxf6 Qxf6 8.Bb5+ Bd7 9.Ne5

Black has only 9...Bd6 to obtain equality, as other lines give white an easier game :

9...Qf4 10.Qe2 Bd6 11.Rf1 Qxh2 12.Nxd7 Qh4+ 13.Rf2 Qh1+ 14.Kd2 (+=)

9...Qh4+ 10.g3 Qxd4 11.Qe2 (++)

9...Bxb5 10.Nxb5
   10...Qh4 11.g3 Qe4+ 12.Kf2 (+=)
   10...Na6 11.Qe2 cxd4 12.Rf1 (++)

9...Bc6 10.Rf1 (++)

9...cxd4 10.Qxd4 Bxb5 11.Nxb5 Bb4+ 12.c3 (+=)

9...a6 10.Rf1 Qh4+ 11.g3 Qxd4 12.Qe2 
   12...Bxb5 13.Nxb5 Qb4+ ( 13...axb5 is answered by 14.c3 ) 14.Nc3 Nc6 15.000 (+=)
   12...axb5 13.Rd1 (+-)

9...Nc6 10.Rf1 (+=)

9...Be7 10.Qe2 (+=)

Returning to the only black defense 9...Bd6 10.Rf1

A little help from our silicon friend indicates that 10...Qe7 11.Rxf7 Qh4+ 12.Rf2 (=) is black's only resource

If you are unfortunate enough that you opponent has found these moves behind the board, you might want to check out my next blog for details.


  1. Great work Guido - but what is actually wrong with 9.00

  2. I have known for about 10 years that 6.Bg5 c5 is a rare line that gives Black a good chance at equality. Both the main line 7.Bxf6 and the less popular 7.d5 score 80% in my database. Practical chances favor White. If Black wants to win, this is not his best hope for an advantage in the Euwe. After 7...Qxf6 8.Bb5+ (8.d5!?) Bd7 and your idea 9.Ne5! is excellent. The main line usually works for White, but Black can make it difficult with 9.0-0 cxd4 10.Nxd4 Qg6! 11.Bd3 f5 12.Ncb5 when White has some play. Also interesting is 9.d5 a6 10.dxe6 when there are four captures for Black, but only 10...fxe6 is any good. Now 11.Bxd7+! Nxd7 12.0-0 0-0-0 13.Qe2 Be7 14.Rae1 White is okay. After 9.Ne5! Bd6 10.Rf1 Qe7 11.Nxd7 Nxd7 12.Bxd7 Qxd7 13.dxc5 Bxh2 14.Qxd7+ Kxd7 15.Rxf7+ Kc6 16.0-0-0 Be5! 17.Re1 with slightly better endgame for White. - Tim Sawyer