Blackmar-Diemer Gambit Accepted

Jan 17, 2016, 2:31 PM |

The starting point of the Blackmar-Diemer Gambit may be reached via various move orders. Below are three of the most common move orders:

  1. 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3
  2. 1.d4 Nf6 2.f3 d5 3.e4 dxe4 4.Nc3
  3. 1.d4 Nf6 2.Nc3 d5 3.e4 dxe4 4.f3

A standard tabiya has now reached with Black to move.

Black may decline the gambit pawn, or accept with 4.exf3 at which point White may recapture with either the Queen (5.Qxf3), or with the Knight (5.Nxf3).

Emil Diemer himself referred to 5.Qxf3 as the Classical Double Pawn Sacrifice, but it is also known as the Ryder Gambit. After 5.Qxf3 White offers a second gambit pawn since the White queen no longer protects d4 from her new post on f3. Droidfish feat. Stockfish Six (6) evaluates the position after 5.Qxf3 at a search depth of 29 ply as follows:

  1. [29] –0.91: 5...Qxd4 6.Be3 Qd8 7.Nh3 c6 8.Bd3 Bg4 9.Qg3 Nbd7 10.Ng5 Bh5 11.0–0 e6 12.Nge4 Qa5 13.a3 0–0–0 14.h3 Bg6 15.b4 Qe5 16.Bf4 Qd4+ 17.Be3 Nxe4 18.Nxe4 Qe5 19.Bf4 Qd5 20.Nf2 Bxd3 21.Nxd3 ;
  2. [29] –0.89: 5...a6 6.Nge2 Nc6 7.Be3 e5 8.0–0–0 Bg4 9.Qf2 exd4 10.Bxd4 Nxd4 11.Rxd4 Bd7 12.Rd2 Bd6 13.g3 0–0 14.Bg2 Qc8 15.h3 h6 16.Kb1 Be5 17.g4 c6 18.a3 Re8 19.Rhd1 Qc7 20.Qc5 Rad8;
  3. [29] –0.62: 5...Nc6 6.Bb5 Bd7 7.Nge2 a6 8.Ba4 e6 9.Bg5 Be7 10.0–0 0–0 11.Rad1 Nd5 12.Bxe7 Ncxe7 13.Nxd5 Bxa4 14.Nxe7+ Qxe7 15.b3 Bc6 16.Qg3 b6 17.c4 Rad8 18.Nc3 f6 19.Rfe1 Qf7 20.Qd3 Rfe8 21.d5 exd5 22.Rxe8+ Rxe8 23.cxd5;
  4. [29] –0.62: 5...g6 6.Be3 Bg7 7.h3 c6 8.0–0–0 Be6 9.Kb1 0–0 10.Nge2 Nd5 11.Nxd5 Bxd5 12.Qf4 e5 13.Qf2 Na6 14.Nc3 e4 15.Bxa6 bxa6 16.h4 h5 17.b3 f5 18.Rhf1 Bf7 19.Ne2 Qb6 20.Bg5 a5 21.Nf4;
  5. [29] –0.48: 5...e6 6.Bf4 Nc6 7.0–0–0 Bd6 8.Kb1 0–0 9.Bc4 Bxf4 10.Qxf4 a6 11.Nf3 b5 12.d5 e5 13.Qh4 Nd4 14.Bd3 Nxf3 15.gxf3 g6 16.Qh6 Bb7 17.Rhg1 Bxd5 18.Ne4 Re8 19.Be2 c6 20.h3 Nxe4;
  6. [29] –0.46: 5...Bd7 6.Bf4 Nc6 7.d5 Bg4 8.Qd3 Nb4 9.Qb5+ Bd7 10.Qxb4 e5 11.Qc4 exf4 12.0–0–0 Be7 13.Qxf4 0–0 14.Nf3 Ng4 15.Re1 Bd6 16.Qd4 Re8 17.Rxe8+ Qxe8 18.Kb1 a6 19.Bd3 Qe3 20.Ne4 Qxd4 21.Nxd4 Ne3 22.Nxd6 cxd6 23.Re1 Nxg2;
  7. [29] –0.40: 5...c6 6.Qf2 g6 7.Bd3 Bg7 8.Nf3 0–0 9.h3 Na6 10.a3 Bf5 11.Bxf5 gxf5 12.Qg3 Kh8 13.Qh4 Nc7 14.Bg5 Ne6 15.0–0–0 Nxg5 16.Nxg5 e6 17.Rhe1 h6 18.Nf3 Nd5 19.Qxd8 Raxd8 20.Nxd5 cxd5 21.Ne5;

Recapuring with the Knight, 5.Nxf3, is statistically the more common approach. At a search depth of 31 ply, Droidfish feat. Stockfish Six (6) calculates a range of 22 centipawns among the numeric evaluations of the top seven principle variations (PV) versus 51 centipawns among the top seven PV following 5.Qxf3. 5.Nxf3 is more favorably evaluated -0.44 vs. -0.91, a difference of 47 centipawns among the most highly evaluated continuations of each.

  1. [31] –0.44: 5...c6 6.Bd3 Bg4 7.Be3 e6 8.Qe2 Bb4 9.a3 Ba5 10.h3 Bh5 11.g4 Bg6 12.Bd2 Nd5 13.Bxg6 hxg6 14.Ne4 Bxd2+ 15.Qxd2 Qc7 16.0–0–0 Nd7 17.Neg5 Qf4 18.c4 Qxd2+ 19.Kxd2 N5b6 20.Kd3 Ke7 21.Rhe1 Raf8 22.b3 Nf6 23.Kc2 Nbd7 24.Ne5 a6 ;
  2. [31] –0.42: 5...a6 6.Bg5 e6 7.Ne4 Nbd7 8.c3 h6 9.Bh4 Be7 10.Nxf6+ Bxf6 11.Bxf6 Nxf6 12.Bd3 0–0 13.0–0 b6 14.Ne5 Bb7 15.Qe2 Nd7 16.Rae1 Nxe5 17.Qxe5 a5 18.Qg3 Kh8 19.a3 c5 20.Be4 Bxe4 21.Rxe4 Qe7 22.Qe5 Rfd8 23.dxc5;
  3. [31] –0.39: 5...e6 6.Bg5 Nbd7 7.Bd3 h6 8.Be3 a6 9.Qe2 Be7 10.Ne4 Nd5 11.Bd2 0–0 12.0–0 c5 13.c4 N5f6 14.Bc3 Nxe4 15.Bxe4 Nf6 16.Bc2 b6 17.Qf2 Ng4 18.Qd2 Bb7 19.h3 Nf6 20.Ne5 Bd6 21.Bd3 cxd4;
  4. [31] –0.37: 5...g6 6.Bg5 Bg7 7.h3 0–0 8.Qd2 c5 9.dxc5 Qa5 10.Bc4 Qxc5 11.Qd4 Qxd4 12.Nxd4 h6 13.Bh4 Nbd7 14.0–0–0 Nb6 15.Bb3 Bd7 16.Rhf1 g5 17.Bf2 e6 18.Kb1 Rfd8 19.Rfe1 Nbd5 20.Nxd5 Nxd5;
  5. [31] –0.34: 5...Bf5 6.Bd3 Bxd3 7.Qxd3 c6 8.Bd2 e6 9.0–0–0 Nbd7 10.Kb1 a5 11.Rde1 Qc7 12.Ng5 Bb4 13.Rhf1 0–0 14.h3 Qd8 15.a3 Bxc3 16.Qxc3 Qb6 17.Qd3 h6 18.Ne4 Nxe4 19.Rxe4 Rfd8 20.c4 Nf6 21.Rxf6;
  6. [31] –0.28: 5...Nc6 6.Bb5 e6 7.Bg5 Be7 8.0–0 0–0 9.Qd2 Rb8 10.Rad1 Bd7 11.Bc4 a6 12.Qf4 b5 13.Bd3 Nh5 14.Qh4 Bxg5 15.Qxg5 Qxg5 16.Nxg5 h6 17.Nge4 Nxd4 18.Nc5 Bc6 19.Nxa6 Rbc8 20.Ne2 e5 21.Nxd4;
  7. [31] –0.22: 5...a5 6.Be2 g6 7.Bg5 Bg7 8.Qd2 0–0 9.0–0–0 c6 10.Bh6 a4 11.Bxg7 Kxg7 12.a3 Bg4 13.Kb1 Nbd7 14.Rhf1 Bxf3 15.Bxf3 Nb6 16.g4 Nfd5 17.Bxd5 Nxd5 18.Nxd5 cxd5 19.h4 e6 20.h5 b5 21.Rde1;