About forcing a checkmate Could a player sacrifice 3 of his pieces , the opponent's King being forced to take each piece in a sequence of moves where the opponent's King lands on a space where it is promptly checkmated? A kind of 3-move forced checkmate. Could this be done with 4 moves?
White to play and mate in 4, while forcing the black king to capture on each move:

[fen "1r2qrnk/3R1bRp/pp2nBpp/p3P3/4B3/5PPQ/PPP3N1/1K6 w - - 0 1"]


Solution:


   1.Rxh7 Kxh7   2.Bxg6 Kxg6   3.Qf5 Kxf5   4.Nh4#