Problemschachaufgabe 641

Hier der Originalkommentar von John Nunn aus der englischen Zeitschrift "The Problemist":

The game-like position of the problem features some typical otb motifs, but there’s
something special in store! 1.Se5! (White needs his knight in the attack; grabbing
the exchange by 1.Bxf7? g5! 2.Qe1 Sf4+ 3.Kf1 Qxf7 is not enough to win as
White’s rook is out of play and his king exposed) 1...Rf8 (if White can keep his
pieces active then winning the exchange will suffice for victory; for example,
1...Sd8 2.Sxf7+ Sxf7 3.Ra1 Qb7 4.Rf1 Sg5 5.Bf5 and White consolidates his extra
material) 2.Bf7! (clearing g6 for mate or possible win of the queen; 2.Bf5? Sf4+!
3.Qxf4 Sh5 regains the piece with a clear draw, while 2.Bxh7? Sf4+ 3.Qxf4 Kxh7
4.Qf5+ Kg8 is safe for Black) 2...Sf4+! (this active counterplay causes the most
difficulty; 2...g5 3.Sg6+ Kg7 4.Sxe7 gxh4 5.Bxe6 wins a piece) 3.Qxf4 Sh5
(3...Rxf7 4.Sxf7+ Qxf7 gives White a decisive material plus) 4.Qg3!! (the star
move of the study, a spectacular retreat of the queen from one attacked square to
another, threatening simply Bxh5; 4.Qf5? g6 5.Sc6 Qxf7 is only a draw) 4...Sxg3
(4...Rxf7 5.Sxf7+ Qxf7 6.Qb8+, 4...g6 5.Qc3 and 4...Rd8 5.Bxh5 are all hopeless)
5.Sg6+! hxg6 6.hxg3+ Qh4 7.Rxh4#