Giving away the advantage in the dragon
This was a slow, USCF rated game (30/90 SD/60, d/5). I spent 16 minutes on this move and, according to Stockfish, gave away my ~3 point advantage.
The position after 18 .. Nb6:
I evaluated two different moves: one was spicy and exciting (19. gxh5), the other was safe (I thought) and methodical (19. Nc3). I didn't see a clear win with gxh5 and saw my kingside deteriorating (analysis below). Also I didn't get the sense that the safe move was giving away an advantage, so I went with Nc3.
I'm trying to figure out what I missed that made Nc3 so bad.
An evaluation of the position.
Material is equal.
* Kingside attack is strong. Pawns are ready to strike. Rooks are in position. Black King has few defenders.
* Outpost knight on b5 slows down black's usage of the half-open c file.
* Half-open d file, but not useful at the moment.
* a pawn is loose.
* Dragon bishop has big scope.
* Half-open c file.
* Not many cracks in the defense, besides h5 pawn.
* Unsafe king.
* Sad rooks.
What does this do?
* It protects undefended a pawn.
* keeps kingside from getting devastated. The Knight was pretty powerful there, but it will lose its support.
* It gives black access to c7. Giving a nice square to black's queen.
What does this do?
* Go after the king! My rooks and queen are positioned to do some damage on the kingside. Downside: I let my king get exposed. I calculated: 19. gxh5 Nxa4 20. hxg6 Bxb2+ 21. Kb1 Rc8 22. gxf7+ Kxf7 Qg5. I wasn't able to see a clear win here so I went for the move I thought was safer. Hold the position together, I thought the kingside storm could wait.
I'm not sure what to conclude here.
1. I don't see a win with gxh5. It seems bad for black, but don't see a clear plan forward.
2. I don't see why Nc3 gives away the advantage. Maybe because it gives black better access to the c-file? Is this worth 3 points?