Let's cut to the chase. My analysis is that the best continuation for both sides is the following:

39. Qxg6 Ra1+ 40. Kh2 Qd6+ 41. Qxd6+ Bxd6+ 42. g3 Nxd4 43. cxd4. (Most of those moves are forced.) If you agree we can go on from there.

This is very embarrassing -- not just because I was mistaken, but because in other lines I looked at I did notice the check on d6 and the discovered attack on whites's or .

After 39. Qd5+ Qd6 40. Rh7+ Be7 (40...Kc8 is also playable), white doesn't have anything (if 41. Rxe7+ Kxe7 42. Bc5, then 42...Ra1#). So I guess I have to exchange s.

You said earlier that you "Look forward to playing this out as I think it will definitely add to my endgame knowledge." I don't want to rob you of your fun, so I'll leave the choice up to you.

If you want to continue, let's try to speed it up. Assuming that after 40. Bc5+ you play 40...Kf7, I will play 41. Rxf8+ Rxf8 42. Bxf8 Kxf8 43. f4. If you accept that continuation, your 43rd move is next.

You wrote that "master strength players and above usually have very good reasons for their moves." Well, yes, but masters can miscalculate too. Sometimes a sacrificial attack fails abjectly. But Chessgames.com (usually) doesn't choose those games for its puzzles, so the Puzzle of the Day makes the pros look more infallible than they really are.

Yes, I thought that 39...Nxd7, was stronger, as your would probably be freed to attack my queenside s. I also thought that 34...Nc4 was stronger than 34...Nc6, but I didn't look at it in any detail.

Black wins with 48...g5, followed by 49...Nb6. This blocks the advance of white's b- while defending black's own on c4.

Then black's marches over by way of c5 to take the b-. (He can always force the opposition, preventing white's from defending it; the only tempo white has is g3.) If necessary, his can go to d7 to keep the f- from promoting. Then the black and push white's down to the bottom of the board. In the final position,

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Black wins regardless of whose move it is. Black can always avoid stalemate by moving the .

I've gone back over the moves and, though white could have prolonged the game by avoiding exchanges and possibly gotten a draw, I don't see any way for him to win.