Editing Philidor Defence (section)

===3...Bg4?!===
Inferior is 3...Bg4{{chesspunc|?!}}, in light of 4.dxe5 Bxf3 (Black cannot recapture since 4...dxe5{{chesspunc|?}} 5.Qxd8+ Kxd8 6.Nxe5 wins a clean pawn; or, Black can gambit a pawn with 4...Nd7, the [[Adolf Albin|Albin]] Variation<ref>Hooper & Whyld 1996, p. 6. ''Albin Variation''.</ref>) 5.Qxf3 (or White can obtain an endgame advantage with 5.gxf3 dxe5 6.Qxd8+ Kxd8 7.f4{{chesspunc|+/−}} [[Géza Maróczy|Maróczy]]<ref name="2C_note7">Matanović 1981 (Vol C), p. 196, n. 7.</ref>) 5...dxe5 6.Bc4 giving White the advantage of the {{chessgloss|bishop pair}} in an open position as well as a large {{chessgloss|development}} advantage. Black cannot block the attack on the f7-pawn with the "natural" 6...Nf6? because White wins a pawn with 7.Qb3 (played in the famous "[[Morphy versus the Duke of Brunswick and Count Isouard|Opera Game]]", where Morphy as White refrained from taking the b7-pawn and retained a strong {{chessgloss|initiative}} after 7...Qe7 8.Nc3). Black does better with 6...Qf6 7.Qb3 Bc5 8.0-0 Bb6 9.a4 a5 10.Nc3 Ne7 11.Be3 Nd7 12.Rad1+/−, or 6...Qd7!? (Maróczy).<ref name=2C_note7 />