Tarrasch Variation, Chistyakov Defense

The Chistyakov Defense arises from the Open System of the Tarrasch Variation when Black answers 4. exd5 with 4...Qxd5 instead of 4...exd5. The idea is to avoid the isolated queen's pawn that often follows the pawn recapture. Because White's knight already stands on d2, Nc3 is unavailable to gain time against the centralized queen. Black intends to collect the d4-pawn with ...cxd4. White normally lets it go, expecting to recover it while gaining a modest lead in development by chasing the queen. This treatment is now regarded as the main line of 4. exd5.

The usual reply is 5. Ngf3, with 5. dxc5 a distant second. After 5. Ngf3 cxd4 6. Bc4, the bishop strikes the queen and Black chooses a retreat square. 6...Qd8 is the Eliskases Variation. The Modern Line goes 6...Qd6 7. O-O Nf6 8. Nb3 Nc6 9. Nbxd4 Nxd4 10. Nxd4 a6. Material is level there, and Black's e-pawn faces White's extra queenside pawn. The game turns on whether White's development outweighs Black's sound structure. The engine rates the starting position as roughly balanced, and White scores only slightly better than Black.