Winning a "refuted" BDG position is not always easy.

Yesterday evening, I played in my local chessclub and my opponent ventured a Blackmar Diemer against me. It's the second time this month, seems like my efforts to promote the gambit are well received...

Lesage - De Bouver, Mechelen 14-OCT-2011
1.e4 d5 2.d4 dxe4 3.Nc3 Nf6 4.f3 ex3 5.Nxf3 Bf5
I had never played my opponent, but I knew he had an agressive style. I choose the Gunderam defense

6.Bc4 c6
Transposing in the Ziegler ( aka O'Kelly ) defense

7.Ne5 e6 8.00

I was considering to play Welling's line, 8...Bxc2, but what if my opponent knew about the refutation 9.Nxf7 ? So I choose to chicken out and play on the safe side.

8...Bg6 9.Be3 Nbd7 10.Nxg6 hxg6 11.Qf3 Qc7 12.h3

12...000 would have been great now, but I choose the inferior plan

12...Nb6 13.Bd3 Nd5 14.Nxd5 exd5

My supposed opening advantage has completely evaporated.

15.Bg5 Be7 16.c4 000
Choosing once again the inferior option. 16...00 is better.

17.c5 Rde8 18.b4 Nh5 19.Bd2

19...Qg3 20.Qxg3 Nxg3 21.Rxf7 Bf6 22.Bxg6 Bxd4+ 23.Kh2 Bxa1 24.Kxg3 Be5+ 25.Kg4
The start of white's king odyssee - but this time not to glory, but to potential doom.

25...Rhf8 26.Bf5 Kb8 27.Rd7 Rd8 28.Re7 Bf6 29.Bf4+ Ka8 30.Re3 Rde8 31.Rd3 Re2 32.g3 Rxa2 33.b5 Rb2 34.bxc6 bxc6 35.Ra3 Rb4 36.h4 Rb5 37.Bd6 Rb4+ 38.Kh5

A blunder of my opponent.
38...Rh8+ 39.Kg6

Due to a lack of time, I failed to see the (easy) win after 39...Rh6+ 40.Kf7 Rb7+ 41.Kg8

and I could have ended the game with the simple 41...g6!!!

But alas, I failed to see the line and had to agree to draw after 39..Rb7 40.Bf4 as white's bishops proved to be great defenders.

Bottomline - beating a so-called refuted (?) Blackmar Diemer line is not that easy as the right moves need to be played again and again.