Final position — Black delivers mate
King's Gambit: Knight Mate (Trimpi–Kaplan)
Black wins in 9 moves by checkmate. (Trimpi - Kaplan, Pennsylvania 1982)
The moves
| 1. | e4 | e5 |
| 2. | f4 | exf4 |
| 3. | Nf3 | g5 |
| 4. | Nc3 | g4 |
| 5. | Nd4 | Qh4+ |
| 6. | Ke2 | Bc5 |
| 7. | Nf5 | Qf2+ |
| 8. | Kd3 | Nc6 |
| 9. | Qe2 | Ne5# |
How the King's Gambit: Knight Mate (Trimpi–Kaplan) works
The King's Gambit: Knight Mate (Trimpi–Kaplan) is a classic chess opening trap arising from the King's gambit. In this line Black delivers checkmate on move 9, punishing a natural-looking but losing idea from White.
The full sequence runs 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Nc3 g4 5.Nd4 Qh4+ 6.Ke2 Bc5 7.Nf5 Qf2+ 8.Kd3 Nc6 9.Qe2 Ne5#. Each move looks reasonable, which is exactly why the trap is so effective over the board — White walks into it while trying to play "normal" developing moves.
This pattern is well known from master and correspondence play (Trimpi - Kaplan, Pennsylvania 1982). Recognising it early lets you either spring it as Black or sidestep it as White.
Practice this trap move-by-move
Open the King's Gambit: Knight Mate (Trimpi–Kaplan) 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.