Sicilian Defense: what to play after Nf3?

In this Sicilian Defense position, Black's most mathematically favorable move according to computer analysis is Bg4, which carries an engine evaluation of -0.35. By immediately developing the light-squared bishop outside the pawn chain to pressure the f3 knight, Black fights directly against White's control of the center. Although Nc6 remains the most popular human choice, Bg4 offers a concrete and effective approach to active piece play.

Developing the Bishop with Bg4

Choosing Bg4 accounts for 19.4% of games in the database (266K recorded), with White scoring 46.3% from this position. Because White has pushed the e5 pawn, Black takes the opportunity to develop the light-squared bishop before playing a move like e6. The primary engine continuation follows Bg4 Bb5+ Nd7 h3 Bxf3 Qxf3, where Black trades the bishop for the knight to relieve pressure on the center while comfortably developing the remaining pieces. Another viable piece development is Bf5, played in 10.5% of games (144K recorded) with an engine evaluation of -0.22 and a 48.6% White scoring rate, continuing Bf5 d4 e6 c3 Nc6 Be2.

The Popularity of Nc6 and Other Alternatives

The overwhelming favorite among human players is Nc6, which appears in 66.1% of games (907K recorded). It scores an engine evaluation of -0.12, with White scoring 47.1%, and commonly leads to Nc6 Bb5 Bg4 Bxc6+ bxc6 d3. More patient setups include the flank move a6, chosen in 3.7% of games (50K recorded, -0.12 evaluation, 46.5% White score), which leads into a6 d4 Nc6 dxc5 Bg4 a3. Finally, Qc7 represents a rare try at 0.3% of games (4.3K recorded) with an evaluation of -0.12 and a 50.6% White score, running Qc7 d4 Bg4 Bb5+ Nc6 c4.