Classical Variation, Giuoco Pianissimo, with a5

This line reaches the Giuoco Pianissimo through the order 4. O-O Nf6 5. d3, with Black inserting 5...a5 before committing to ...d6, and White answering 6. c3. The rook pawn claims queenside space and makes White's usual b4 expansion harder to arrange, since the pawn on b4 would be met by ...axb4. It also gives the c5-bishop a retreat to a7 without first spending a tempo on ...a6. The move can be pushed further to a4, a rare option at move six that fixes White's queenside pawns and denies the b3 square to the light-squared bishop.

The most common reply is 6...d6, which transposes into standard Giuoco Pianissimo positions with the a-pawn already on a5. Castling with 6...O-O and the prophylactic 6...h6 follow in popularity. The engine also favors 6...Ba7, tucking the bishop away immediately, and assesses the position as roughly balanced. The play stays slow and positional, with both sides maneuvering behind their central pawns. In online games White scores slightly better than Black, and draws are uncommon.