A flick of the h-pawn

Yesterday I was thinking about two of the ChessLectures I have given this year that featured a surprisingly early (to me) h4. First, the game Krush-Esserman, which I featured here in December and lectured on in January: 1. d4 f5 2. c4 Nf6 3. Nc3 g6 4. h4 Bg7 5. h5!...