Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bc4/3...Nf6/4. d4/4...exd4/5. O-O/5...Nxe4/6. Nc3/6...dxc3/7. Bxf7/7...Kxf7/8. Qd5/8...Kf6/9. Re1/9...Ne7/10. Qxe4/10...Kf7

= Nakhmanson Gambit, Kf6 Defence, Rook Attack =

10...Kf7
Black's king is heading for the safety of g8. If White sees the king slipping through her fingers and plays a panic check, obvious moves will be enough for Black  to stave off checkmate: 11.Qf4+ Kg8 12.Ng5 (or 11.Ng5+ Kg8 12.Qf4) Qe8  13.Qc4+ d5:


 * 14.Rxe7 Bxe7 15.Qxd5+ Kf8 16.Qf3+ Bf6 0-1
 * 14.Qxc7 h6 makes a hidey-hole for the king on h7. If the White knight had checked on e5 instead of g5, Black would now have 14...Nc6! taking advantage  of the undefended rook on e1.

So White needs to forget about checkmate and focus on winning back the piece with 11. Bg5.