Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...Nf6/4. d3/4...Ne7

Mortimer variation C60—99 Anti-Berlin 4...Ne7 · Mortimer variation 4...Ne7 in the Anti-Berlin is the Mortimer variation. On the surface this is a strange move: Black violates principles by moving their knight a second time in the opening, at the same time inhibiting the development of their king-side bishop. Black's idea is to free the c6 square for their pawn, and chase White's bishop away that way. 5. Nxe5? falls into the Mortimer trap. 4...Ne7 appeared to undefend the e5 pawn. As the opening manoeuvres of the Spanish game centre around these e-pawns, White may think to punish Black's passive move by snapping up the e-pawn. But, after 5...c6 6. Bc4 (or Ba4), Black has 6...Qa5+!, forking the knight. Therefore 5. O-O is the mainline, removing the king from the centre and any ideas of Qa5+. After 5...c6 6. Ba4 Black must defend e5, either with 6...d6 or by moving the knight again, 6...Ng6. History The Mortimer variation is named after James Mortimer (1832―1911), who played it at a tournament in London in 1883.Rosenthal v Mortimer, 1883 - Chessgames.com Theory table 0 Mortimer variation 5. O-O c6 6. Ba4 Ng6 7. c3 Be7 8. Re1 O-O 9. Nbd2 5. Nxe5? c6 6. Bc4 Qa5+ 7. Bd2 Qxe5 -- Mortimer trap References See also Ruy Lopez, Mortimer Trap