Paulsen Variation

The Paulsen Variation, 3. Nc3, is the most common way of meeting the French at the highest level and is generally regarded as White's most testing option. The knight protects e4 while adding a second attacker to d5. Unlike 3. Nd2, the Tarrasch, it leaves the c1-h6 diagonal clear, so the dark-squared bishop can come out to g5 or e3. The trade-off is that the knight on c3 can be pinned by ...Bb4, and that possibility shapes much of what follows.

Black's two principal answers keep the d5-e4 tension and develop a piece. 3...Nf6, the Classical Variation, is met mainly by 4. e5, the Steinitz Variation, where play typically runs 4...Nfd7 5. f4 c5 6. Nf3 Nc6 7. Be3 with a small plus for White, or by 4. Bg5, after which 4...dxe4, 4...Be7 and 4...Bb4 are all seen. 3...Bb4, the Winawer, pins the knight and usually provokes 4. e5. After 4...c5 5. a3 Bxc3+ 6. bxc3, Black has given up the bishop that the e6-d5 chain makes good, in return for damaging White's queenside pawns, and the play is often sharp.

The Rubinstein Variation, 3...dxe4, releases the tension at once. Its practical appeal is economy: after 4. Nxe4 it reaches the same position as 3. Nd2 dxe4 4. Nxe4, so Black can answer both third moves with one system. It is nearly as popular as 3...Nf6 in Lichess games, though it scores a little worse for Black. Less common is 3...Nc6, the Hecht-Reefschläger, which blocks the c-pawn and so gives up the usual ...c5 break; a typical continuation is 4. Nf3 Nf6 5. e5 Ne4. The Marshall Gambit, 3...c5, strikes at the center before White has played e5 and is considered dubious, since 4. exd5 exd5 5. dxc5 Bxc5 6. Qxd5 simply wins a pawn. Moves such as 3...Be7, 3...a6 and 3...h6 appear only occasionally.

Louis Paulsen employed the knight development against Ignatz von Kolisch in London in 1861, and Kolisch answered with both 3...Bb4 and 3...dxe4. Heyde's 1891 monograph on the French judged the line to be White's best and preferred 3...Nf6 to 3...Bb4 as Black's reply. The Winawer was revived in the 1920s, when Nimzowitsch and later Botvinnik brought new ideas into it. In online play White scores slightly better than Black from this position, and the engine considers it close to balanced.