Agincourt Defense, Bogoljubow Defense

The Bogoljubow Defense, 4...Bd6, is a sideline of the Neo-Catalan in which Black develops the dark-squared bishop to d6 instead of the more modest e7, pointing it toward White's kingside. 5. O-O is by far the most common reply. The rarer 5. cxd5 has scored well for Black in practice. 5. d4, the engine's preferred move, heads for Catalan structures. The engine assesses the position as a slight edge for White.