Final position — Black is winning
Vienna Game: Knight Fork
Black wins in 9 moves with a decisive material gain. (Alekhine - De Cossio, San Sebastian 1944)
The moves
| 1. | e4 | e5 |
| 2. | Nc3 | Bc5 |
| 3. | Bc4 | Ne7 |
| 4. | d3 | Nbc6 |
| 5. | Qh5 | O-O |
| 6. | Bg5 | Qe8 |
| 7. | Nd5 | Bb6 |
| 8. | Nf6+ | gxf6 |
| 9. | Bxf6 |
How the Vienna Game: Knight Fork works
The Vienna Game: Knight Fork is a classic chess opening trap arising from the Vienna Game. In this line Black wins decisive material by move 9, punishing a natural-looking but losing idea from White.
The full sequence runs 1.e4 e5 2.Nc3 Bc5 3.Bc4 Ne7 4.d3 Nbc6 5.Qh5 O-O 6.Bg5 Qe8 7.Nd5 Bb6 8.Nf6+ gxf6 9.Bxf6. 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 (Alekhine - De Cossio, San Sebastian 1944). Recognising it early lets you either spring it as Black or sidestep it as White.
Practice this trap move-by-move
Open the Vienna Game: Knight Fork 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.