Classical Variation, Giuoco Pianissimo, with a6

With 5...a6 Black makes a useful waiting move before choosing between the standard setups. The pawn gives the c5-bishop a retreat to a7, so a later b4 or d4 from White does not gain time, and it rules out Bb5 ideas. Black holds back ...d6 or castling for a move, and play often transposes to the main lines of the Pianissimo. In the Main Line the same ...a6 appears at move seven. The game stays quiet and maneuvering, with both sides arranging pieces behind a closed center rather than seeking early contact.

Castling with 6. O-O is the most common reply and the engine's first choice. The retreat 6. Bb3 is also frequent. It moves the bishop off c4 before ...b5 can harass it, and White scores somewhat better after it. The thrust 6. a4 gains queenside space and discourages ...b5 altogether. The engine also suggests 6. h3, which takes g4 away from Black's light-squared bishop. The engine considers the position roughly level. In online games White scores slightly better than Black, and draws are uncommon.