I only saw that 22.Ng5 hxg5 23.Qxh7 Qxf6 24.b3 leaves white up a full pawn at best. No other move besides Ng5 leads to this kind of advantage from what I could see, so Ng5 passes the test as best move. That's when I would play the move and hit the clock.

Missing the killer move, 23.Rxf7+!, could be a problem if there was another initial candidate that competed with 22.Ng5. Because 23.Rxf7+ makes the entire line a very strong one, if there was another candidate that seemed strong compared to 22.Ng5, then it becomes possible to miss a forced mate over grabbing a few pawns for example. But here, nothing seems to compete with 22.Ng5 so you can get away with missing 23.Rxf7+.

Actually, white has a checkmate path even if black responds by taking with his pawn 22. Ng5 hxg5
23.Rxf7+, if black takes then white just brings the queen up and mates.

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If black accepts the queen sacrifice with 16...Rxb5, then white goes up two pawns after 17 Raxf7+ (not Rfxf7+) Ke8 18 Rf8+ Kd7 19 Rxd8+ Kxd8 20 Nxb5.

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Don't take it personally, but from reading some of your previous kibitzes it sounds like more than a slump.

Still licking my wounds after yesterday's spoiler - but after 22 Ng5 I cannot see any way out for Black. Can it really be that easy? [snip] Time to check:
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Missed it - if hxg5 I had intended Qxh7?. Useful comment from <patzer2: With 22. Ng5! White whips up a mating attack ...The followup 23. Rxf7+! is important, since the alternative 23. Qxh7?! Qxf6 24 b3 gives Black practical drawing chances>. <patzer2'>s ending can be reachd in following Crafty End Game Trainer llink: http://www.chessvideos.tv/endgame-t... I have found no way of winnig for White starting 23 Qxh7: of course there is a quick mate starting Rxf7+. As Black Crafty defends with 23.Qxh7 Qxf6 24.b3 d5 (forestalling the intended c4) 25.Qd3 Rc8 26.c4 Kg8 27.h3 Qb2

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It is very interesting how Crafty has equalised even though a pawn down. Crafty now threatens ...dxc4 bxc4 Qg6+ winning my R, so I try 28.Kh1 leading to 28...Qe5 29.Qf1 f5 30.Qd3 Qf6 31.Ra6 Qe5 32.Ra7 Qf6 33.Qd1 (a last attempt to avoid the draw) dxc4 34.bxc4 Rxc4 35.Ra8+ Kg7 36.Qd7+ Qf7 37.Qxf7+ (White's King is too vulnerable to try for more) Kxf7 38.Kg1 Rc2 39.Kf1 Black is now better (!) but I can draw the R and P ending by playing carefully: 39...Kf6 40.Ra5 f4 41.exf4 gxf4 42.Kg1 e5 43.Kf1 e4 44.Kg1 e3 45.Kf1 Rf2+ 46.Kg1 Rd2 47.Kf1 draw,

The young boy they called Grasshopper was tired from many hours of practice, his knuckes bruised and raw from constantly punching posts and tiles. He was secretly hoping for the bit when he would get to play with the sharp swords and the throwing stars.

The sensei breathed in deep of the fragrance of the lotus blossom. He was older than the willow trees on the slopes of Mount Fuji, and the years had given him much wisdom.

"Tell me, grasshopper, which is the most difficult chess piece to master?" asked the venerable sensei.

"The knight?" asked the apprentice, hesitantly. "Because its leap is so unpredictable, like a dragon?"

"Wrong!" said the old man. "The knight is a simple beast. It's move is always from one colour to the next, and its move is always the same length. What is more, the knight is free from the first move of the game. Try again."

"The queen, because she must not be advanced too quickly?"

The sensei smiled gently. "A good answer, little one. But not correct. The most complicated piece is the rook."

Grasshopper was puzzled. "But the rook is so simple! Up and down, left and right."

"You still have much to learn before you can attain mastery. Observe this game of chess. By move 7, white had castled bringing his king rook into the game."

"By move 10, he had cleared all his pieces from the back rank so that his rooks could see each other."

"By move 15, both of his rooks had open or half open files to work with."

"By move 16, one of his rooks had reached the seventh rank."

"Black achieved none of these things. He never castled, never grabbed an open file, never joined his rooks together."

Grasshopper nodded. "I see, master. Yet white then gives away both of his powerful rooks. Why does he do this?"

The sensei smiled, in that infuriatingly smug way that he had. "Indeed, for he had driven the black rooks into such passive positions that mate was assured. Rooks make excellent attackers but very poor defenders."

Grasshopper nodded.

"That is enough for today," says the sensei, wearily. "Remember, true mastery comes when you have learned to handle rooks. And when you can walk on the rice paper without leaving a mark, it will be time for you to leave."

Material: White has N+2P for a rook.

What immediately sticks out in this puzzle is Qxf7#, if not for the h7 rook. Since there are no under- or undefended pieces, it seems like the mate is our true goal. But how to distract the h7 rook? 22. Ng5!

Candidates: 22.Qxf7+; 22.Rxf7+ and 22.Ng5.

The reason for 22.Ng5 is quite simple: 22.Rxf7+ Rxf7 23.Qxh6+ Ke8 24.Qh8+ Rf8 is nothing for W. Thus, W needs one more attacker against f7.

22.Ng5 threatens 23.Rxf7+ Rxf7 24.Qxf7+ mate or even the fork at e6. If B answers 22.Ng5 by 22...hxg5, then 23.Qxh7 and mate to follow. Or 22...Ke8 23.Re7+ loses the Q. Or if 22...Kg8, then 23.Qg6+ Rg7 24.Qxg7+ is mate. It remains only for B to defend hard on f7: 22...Qe8. But 23.Nxh7+ Kg8 24.Qg4+ Kxh7 25.Qg7+ mate.

Time to check.

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