Black usually captures White's KP and invites a pawn exchange
on his K4(e5) (rather than transpose into
Alekhine's Defence
by 3..Kt-Q4), as he keeps the pawn
gain by
4.PxP..QxQ+ch, 5.KxQ..Kt-Kt5 to White's disadvantage.
B-Alt.
White Black
1. P-K4 P-Q3
2. P-Q4 Kt-KB3
3. P-K5? PxP
