Spanish Variation, Rubinstein Variation

The Rubinstein Variation, also called the Rubinstein Countergambit after Akiba Rubinstein, answers 4. Bb5 with 4...Nd4. The knight leaves e5 apparently unguarded and attacks both the b5 bishop and the f3 knight. This avoids the symmetry of the Double Spanish and gives Black a more dynamic game. Engines rate it as level, and online results are evenly split.

The most common reply online is 5. Nxd4 exd4, the Exchange Variation. It usually continues 6. e5 dxc3 7. exf6 Qxf6 8. dxc3, and after 8...Qe5 9. Qe2 Qxe2+ 10. Bxe2 the queens are off and the position is very drawish. Black still scores well in it in online play. Taking the pawn with 5. Nxe5, the Bogoljubov Variation, can lead to very sharp play, and White scores better there. One branch is the Marshall Variation, 5. Nxe5 Bc5 6. O-O O-O. The traditional main line is 5. Ba4, with the Marshall Gambit 5...Bc5 6. Nxe5 O-O as one branch. Other options are the modern 5. Bc4, the Henneberger Variation 5. O-O, and 5. Be2. That last move leads to the Maróczy Variation after 5...Nxf3+ 6. Bxf3 Bc5 7. O-O O-O 8. d3 d6 9. Na4 Bb6.