Monday, June 4, 2012

O'Kelly variation - 7...Bg5 Nbd7 line.

Stefan Bucker focused in 2010 on chesscafe.com on some potential lines in the O'Kelly ( or Ziegler ) defense. I elaborated them in my book "Attack with the Blackmar Diemer".

After 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 c6 5.Bc4 exf3 6.Nxf3 Bf5, Stefan suggested to play 7.Bg5 (diagram).

Today, we will consider the most natural continuation : 7...Nbd7 8.Qe2 e6 9.000 (diagram)

Houdini now suggests 9...Be7 as the strongest move, after which white prepares the breaktrough in the centre with the surprising 10.Bxf6 (diagram).

a/ 10...Bxf6 11.d5
...a1/ 11...cxd5 12.Nxd5 (=)
...a2/ 11...Bxc3 12.dxe6 (=)
...a3/ 11...00 12.dxe6 (+=)
...a4/ 11...Qe7 12.dxe6 (in my book, I sugested 12.d6, but 12...Qd8 is better for black)
......a4a/ 12...fxe6 13.Ne4 (=)
......a4b/ 12...Bxe6 13.Bxe6 (=)
...a5/ 11...Qc7 12.dxe6 fxe6 13.Bxe6 (+=)

b/ 10...Nxf6 11.Ne5
...b1/ 11...Nd5 12.g4 (=) (improving on 12.Nxd5 I wrote earlier)
...b2/ 11...00 12.g4 (+=)
...b3/ 11...Qc7 12.g4 (=)
...b4/ 11...Qb6 12.g4 (+=)
...b5/ 11...Qa5 12.g4 (+=)
...b6/ 11...h6 12.Rhf1 (=)
...b7/ 11...h5 12.h3 (=) (I evaluated this earlier as better for black, but it seems this is equal)
...b8/ 11...Nd7 12.Nxd7 Qxd7 13.d5 (+=)

c/ 10...gxf6 11.Re1
...c1/ 11...Rg8 12.h3 (=) (much better than 12.g3 I suggested in my book)
...c2/ 11...Qc7 12.d5 (+=)
...c3/ 11...Qb6 12.Nh4 (+=)
...c4/ 11...Qb6 12.d5 (+=)
...c5/ 11...Bg6 12.Bxe6 fxe6 13.Qxe6 (=)
...c6/ 11...Bg4 12.d5 (=)
...c7/ 11...Bb4 12.Nh4 (=)
...c8/ 11...Bd6 12.d5 (+=)
...c9/ 11...Nb6 12.d5 (=)

So it seems there is not a single line that gives black an advantage in this so called "refutation" of the Blackmar Diemer gambit ! Guess the critics will have to find another line to prove our beloved opening is refuted.






1 comment:

  1. I didn't know you analyzed this line, but I found something similar on my own here, while I was looking for ways to skirt around refuted lines. The idea emerged from reading someone's "g4!?" suggestion. Obviously this move is preposterous and Nxg4 should refute, but what if the knight were simply removed first? That was sort of my idea... playing Bg5 with the intention to take the knight and possibly facilitate g4.

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