Final position — White delivers mate
King's Gambit: Back-Rank Mate (Cage–McCoy)
White wins in 12 moves by checkmate. (Cage - McCoy, British Postal, 1996)
The moves
| 1. | e4 | e5 |
| 2. | f4 | exf4 |
| 3. | Nf3 | g5 |
| 4. | Bc4 | g4 |
| 5. | O-O | gxf3 |
| 6. | Qxf3 | Qe7 |
| 7. | Qc3 | Bg7 |
| 8. | Qxg7 | Qc5+ |
| 9. | Kh1 | Qxc4 |
| 10. | Rxf4 | Qxc2 |
| 11. | Qxf7+ | Kd8 |
| 12. | Qf8# |
How the King's Gambit: Back-Rank Mate (Cage–McCoy) works
The King's Gambit: Back-Rank Mate (Cage–McCoy) is a classic chess opening trap arising from the King's gambit. In this line White delivers checkmate on move 12, punishing a natural-looking but losing idea from Black.
The full sequence runs 1.e4 e5 2.f4 exf4 3.Nf3 g5 4.Bc4 g4 5.O-O gxf3 6.Qxf3 Qe7 7.Qc3 Bg7 8.Qxg7 Qc5+ 9.Kh1 Qxc4 10.Rxf4 Qxc2 11.Qxf7+ Kd8 12.Qf8#. 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 (Cage - McCoy, British Postal, 1996). Recognising it early lets you either spring it as White or sidestep it as Black.
Practice this trap move-by-move
Open the King's Gambit: Back-Rank Mate (Cage–McCoy) 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.