Blackmar-Diemer Gambit Accepted: Ritter Defense
1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3 exf3 5. Nxf3 b6
The Blackmar-Diemer Gambit Accepted: Ritter Defense is a chess opening classified as ECO D00, reached after 1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3 exf3 5. Nxf3 b6. It is a line of the Blackmar-Diemer Gambit Accepted. White is to move.
In 12.6 million rated Lichess games (blitz and slower), this position was reached 30 times by this move order. White won 67%, 3% were drawn and Black won 30%. The most popular continuation is 6. Bd3 (40% of games).
Engine evaluation: +0.84 (Stockfish, depth 30; best line 6. Ne5 c6 7. Bg5 Be6 8. Qf3 Qxd4)
- ECO
- D00
- Moves
- 10 plies
- FEN
rnbqkb1r/p1p1pppp/1p3n2/8/3P4/2N2N2/PPP3PP/R1BQKB1R w KQkq - 0 6- PGN
1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3 exf3 5. Nxf3 b6
Analyse with Stockfish · Board image (SVG) · Open on Lichess
Results by rating
| Average rating | Games | White / draw / Black |
|---|---|---|
| 0-1499 | 6 | |
| 1500-1999 | 22 | |
| 2000+ | 2 | |
| All | 30 |
Most played moves
| Move | Games | White / draw / Black |
|---|---|---|
| 6. Bd3 | 12 (40%) | |
| 6. Bc4 | 9 (30%) | |
| 6. Be3 | 4 (13%) | |
| 6. d5 | 1 (3%) | |
| 6. Bg5 | 1 (3%) | |
| 6. Bf4 | 1 (3%) | |
| 6. Bb5+ | 1 (3%) | |
| 6. g3 | 1 (3%) |
Master games
1 over-the-board game is classified under this line (White 0%, draw 0%, Black 100%). The strongest:
- CM Thomas Christensen (2143) – FM Sergey Fazulyanov (2350) 0-1 · Titled Tuesday 7th July · 2020-07-07
Search all games of the Blackmar-Diemer Gambit Accepted: Ritter Defense and its sub-variations
Highest-rated Lichess games
- ALF297 (2040) – crickycrck (2064) 1-0 · 2026-09-05 · 180 + 2s
- RedW55 (1998) – Nadal650 (2024) 1-0 · 2026-09-03 · 300 + 0s
- andrei196011 (1987) – trashGuyFromMountain (1960) 1-0 · 2026-09-05 · 180 + 0s
Comes from
Blackmar-Diemer Gambit Accepted 1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3 exf3
More Blackmar-Diemer Gambit Accepted lines (all)
- Blackmar-Diemer Gambit Accepted: Bogoljubow Defense D00
- Blackmar-Diemer Gambit Accepted: Bogoljubow Defense, Kloss Attack D00
- Blackmar-Diemer Gambit Accepted: Bogoljubow Defense, Mad Dog Attack D00
- Blackmar-Diemer Gambit Accepted: Bogoljubow Defense, Nimzowitsch Attack D00
- Blackmar-Diemer Gambit Accepted: Bogoljubow Defense, Studier Attack D00
- Blackmar-Diemer Gambit Accepted: Euwe Defense D00
- Blackmar-Diemer Gambit Accepted: Euwe Defense, Duthilleul Gambit D00
- Blackmar-Diemer Gambit Accepted: Euwe Defense, Zilbermints Gambit D00
- Blackmar-Diemer Gambit Accepted: Gunderam Defense D00
- Blackmar-Diemer Gambit Accepted: Gunderam Defense, Stader Variation D00
- Blackmar-Diemer Gambit Accepted: Holwell Defense D00
- Blackmar-Diemer Gambit Accepted: Kaulich Defense D00
Opening names and moves from the Lichess openings dataset; statistics from the Lichess open database, 2026-09 (CC0), sample of 12.6 million games, bots excluded; evaluations from Lichess cloud analysis (all CC0). Master games from The Week in Chess #920–#1664 by Mark Crowther, used with permission.