“White does not count correctly and plays 1.Qxf7+?? Black, of course, should take the queen with 1...Kxf7, but young beginners often automatically “move their king out of check” instead of looking at the other possibilities of capturing the checking piece or blocking the check. So they play 1...Kd8?? and just lose a pawn! And with the black queen on d8, they often “resign,” since they assume 1.Qxf7+?? is checkmate!”