Instead of the more traditional ...h6, here black opts to block the white pawn from advancing altogether. This is a rare move at the professional level, although not an inherently bad one (although castling kingside becomes more dangerous compared to ...h6 lines). White has a large variety of moves to play; 7. Nf3 develops a piece while 7. Nh3!?, aiming for an eventual Nf4, has also been attempted.