Symmetrical Variation

The Symmetrical Variation arises when White answers the Tarrasch Defense with 4. e3 instead of the main-line 4. cxd5. White simply protects d4 and keeps the dark-squared bishop behind the pawn chain. After 4...Nf6 5. Nf3 Nc6 the pawns and knights mirror each other exactly, and White's only extra asset is the move. The same position can arise from 4...Nc6 5. Nf3 Nf6, and it is also reachable from the Semi-Tarrasch Defense. Because White has not forced an isolated pawn on Black, the line counts as White's main sideline, but it allows Black to equalize quickly.

At move six, White most often plays 6. cxd5, which resolves the central tension. The other main tries are 6. Be2, 6. a3 and 6. Bd3, and the last of these is classified as the Semi-Tarrasch with e3. With the c- and d-pawns still in contact, either side may end up with an isolated queen's pawn, depending on who captures first and when. The engine rates the position as balanced, and practical results are close to even. In online play, decisive games far outnumber draws.