White wins

With Qg7# in the air and the a2-pawn poised to queen, White is on a knife-edge. The instinctive 1.Qc6+? is a mistake, crashing against 1…Ng6, which blocks the check and leaves White helpless.

Instead, the correct move is 1.Qf7! — not only guarding g7 but also threatening 2.Qh7# and 2.Qh5#. How can Black resist now? 1...Be6 falls to 2.Qxe6+ Ng6 3.Qh3+. Thus, to stave off immediate collapse, only something drastic will do:

1…Qh8+!

2.Kxh8 a1=Q+

(2...Ng6+ 3.Kg8 +- )

3.Kg8 Qh8+!

4.Kxh8 Ng6+

5.Kg8 Be6!

An astonishingly cunning idea! The e6-bishop cannot be touched — 6.Qxe6? is stalemate; the double queen sacrifice set the stage for this. So is Black really about to snatch the wQ next turn and wriggle out with half a point? Not quite! White's decisive blow shatters this illusion.

6.Ng5!

Here, Black is beyond saving:
– if 6…Kxg5, 7.Qxe6, and it’s all over.
– if 6…Bd5, 7.Ne6! seals the deal (though not 7.Qxd5?, which runs afoul of 7...Ne7+ fork).
– if 6…Ne7+, 7.Kf8 Ng6+ 8.Qxg6+ Kxg6 9.Nxe6 wins too.

And of course, the main continuation 6…Bxf7+ is answered by 7.Nxf7#.

Note that 6.Nd6?, though resembling the winning move, is refuted by 6…Ne7+! 7.Kf8 Ng6+, allowing Black to escape.

Deceptive, sharp — quintessential Pogosyants!