|The Marshall Defense is a chess opening that begins with the moves|
1.d4 d5 2.c4 Nf6
The Marshall Defense is a dubious variation of the Queen´s Gambit Declined.
It was played by Frank Marshall in the 1920s, but he gave it up after losing with it to Alekhine at Baden-Baden in 1925.
It is no longer used by experienced players.
If White plays e2-e4 too early, Black may equalize (for example, by 3.cxd5 Nxd5 4.e4?! Nf6 5.Nc3 e5! 6.dxe5 Qxd1+ 7.Qxd1 Ng4!).
Instead, White gets a clear advantage with 3.cxd5 Nxd5 4.Nf3! Bf5 5.Qb3.
White may also ignore Black´s provocative second move, and play 3.Nc3, which will usually transpose into normal lines of the Queen´s Gambit Declined (after 3...e6), the Slav Defence (after 3...c6), the Queen´s Gambit Accepted (after 3...dxc4) or the Grünfeld Defence (after 3...g6).