Marshall Defense, Tan Gambit

The Tan Gambit is Black's answer to the main difficulty of the Marshall Defense. After 3. cxd5, recapturing with the knight or queen exposes the piece to gain of tempo, so 3...c6 instead offers a pawn to open lines and speed up development. White currently has the doubled d-pawns on d4 and d5, but taking on c6 removes that problem and leaves White a clean extra pawn. The engine favors 4. dxc6, which is also the most frequent choice, played in about half of all games, and rates White's position as slightly better.

After 4. dxc6 Nxc6 Black has active pieces and open files in return for the pawn, and a typical continuation is 5. Nf3 e5, striking at the center at once. The second most common reply, 4. Nc3, declines the material and allows Black to recapture on d5 with the c-pawn, while 4. Nf3 is a rarer option. In online games the results are close, with White scoring slightly ahead, and draws are unusually rare.