The Main Line is a variation of the Giuoco Piano, catalogued as ECO C50. The line runs 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. Nc3 Nf6 5. O-O O-O, reaching the position shown below after 10 half-moves.
Both sides have pawns in the centre (White on e4, Black on e5). Development is level at three minor pieces each. It is White to move after five moves. Both kings have castled kingside, so play tends to shift to the centre and the opposite flank.
On the Giuoco Piano generally: The 'Quiet Game' — a classical Italian opening where both sides develop bishops to active squares. Leads to rich middlegame play.
You can play through this variation move by move in your browser — Learn mode walks the line with an explanation at each step, and Drill mode replays it from memory so you find out whether you actually know it. No account is required.
See all 9 Giuoco Piano variations →
The Main Line goes 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. Nc3 Nf6 5. O-O O-O. It is a variation of the Giuoco Piano and is catalogued as ECO C50.
The Main Line is ECO C50. ECO codes group openings by their move order, so nearby codes cover closely related lines of the Giuoco Piano.
Stockfish evaluates the position after 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. Nc3 Nf6 5. O-O O-O at +0.18 at depth 18, which is balanced. Engine evaluation is only a starting point — at club level the practical value of a line is mostly about whether you know its plans better than your opponent does.
Both sides have pawns in the centre (White on e4, Black on e5). Development is level at three minor pieces each. It is White to move. Both kings have castled kingside, so play tends to shift to the centre and the opposite flank.