Final position — White delivers mate
Blackmar-Diemer Gambit: Knight Mate
White wins in 11 moves by checkmate. (Welling - Scheeren, Eindhoven)
The moves
| 1. | d4 | d5 |
| 2. | e4 | dxe4 |
| 3. | Nc3 | Nf6 |
| 4. | f3 | exf3 |
| 5. | Qxf3 | Qxd4 |
| 6. | Be3 | Qg4 |
| 7. | Qf2 | Qb4 |
| 8. | O-O-O | Nc6 |
| 9. | Nb5 | Qa5 |
| 10. | Qe1 | Qxe1 |
| 11. | Nxc7# |
How the Blackmar-Diemer Gambit: Knight Mate works
The Blackmar-Diemer Gambit: Knight Mate is a classic chess opening trap arising from the Blackmar-Diemer Gambit. In this line White delivers checkmate on move 11, punishing a natural-looking but losing idea from Black.
The full sequence runs 1.d4 d5 2.e4 dxe4 3.Nc3 Nf6 4.f3 exf3 5.Qxf3 Qxd4 6.Be3 Qg4 7.Qf2 Qb4 8.O-O-O Nc6 9.Nb5 Qa5 10.Qe1 Qxe1 11.Nxc7#. Each move looks reasonable, which is exactly why the trap is so effective over the board — Black walks into it while trying to play "normal" developing moves.
This pattern is well known from master and correspondence play (Welling - Scheeren, Eindhoven). Recognising it early lets you either spring it as White or sidestep it as Black.
Practice this trap move-by-move
Open the Blackmar-Diemer Gambit: Knight Mate in the Trapsterapp to play it out on a live board, drill it in practice mode, and learn how to avoid it when it's set for you — along with the full library of chess traps and gambits, fully offline.