Exchange Variation

With 3. cxd5 White releases the central tension at once instead of developing with 3. Nf3 or 3. Nc3. Black almost always restores material symmetry with 3...cxd5, and the result is a position where each side has a pawn on d-file squares, neither has a c-pawn, and the c-file is open for both. White keeps only the extra tempo of having moved first. Because of this, the line is used as a drawing weapon, and Black players who want to sidestep it often reach the Semi-Slav through the Triangle System, playing ...e6 before ...c6.

The structure gives little to attack. There are no pawn weaknesses, no minority attack as in the Exchange Queen's Gambit Declined, and the bishops on both sides have open diagonals. Play typically revolves around control of the c-file, where heavy pieces are often traded, and around small advantages in piece activity. Wins tend to come only when one side overreaches in trying to unbalance the game. Engines rate the position as roughly balanced. In online play, however, draws are uncommon, and White scores somewhat better than Black.

The main line runs 3...cxd5 4. Nc3 Nf6 5. Nf3 Nc6 6. Bf4 Bf5, the Symmetrical Line, in which both sides mirror each other's development. The Trifunovic Variation reaches the same setup through 3. Nf3 Nf6 4. cxd5 cxd5 5. Nc3 Nc6 6. Bf4 Bf5 and continues 7. e3 e6 8. Qb3 Bb4. There, White's queen eyes b7 and Black responds by pinning the c3-knight. The Schallopp Variation, 3. Nf3 Nf6 4. e3 Bf5 5. cxd5 cxd5 6. Nc3, delays the exchange until Black's light-squared bishop has already left c8. The Boor Attack, 3...cxd5 4. Nc3 Nf6 5. f3, breaks the symmetry by preparing e4.

Black's alternatives to the recapture with the pawn are considered inferior. 3...Qxd5 lets White develop with tempo by 4. Nc3 and seize the center. 3...Nf6 transposes to the Tan Gambit of the Queen's Gambit Declined: Marshall Defense, which is seldom seen at a high level.