Two Knights Variation

After 4. cxd5 exd5 the Tarrasch structure is fixed, and 5. Nf3 is the most natural continuation. White develops a kingside piece, adds pressure on d4 and c5, and postpones the main decision. The choice between the fianchetto plan with g3 and an early dxc5 remains open. The sharper alternative 5. e4, a gambit tested by Frank Marshall, is far less common.

Black's most frequent reply is 5...Nc6. It supports d4 and invites 6. g3, the Rubinstein System, in which the bishop on g2 aims at the isolani. It also meets 6. dxc5 with 6...d4, gaining time against the knight. 5...Nf6 is the second choice and is played almost as often. It develops the kingside first and usually transposes to the same structures. The early 5...cxd4 releases the central tension at once and is less popular. The engine gives White a slight edge. In practice results are fairly close, with White scoring somewhat better and few games drawn.