In the diagram above, I've featured a game that follows the bookline opening for Queen's Gambit Declined. When White plays Bg5, pinning Black's knight to his Queen, I have seen in articles a response of Nd7, however, as I have often wondered in games of different variations, why not respond with a pawn to challenge the bishop? As I see it, the move does little to damage pawn structure; if white allows black to take, thus doubling black's pawns on the g-file, white has opened the h-file for black's rook; if white plays bxnf6, he simply loses his dark-squared bishop, giving black an advantage with the dark squares.
What exactly is the downside to h6?
