Only move that keeps a winning position
Why is this move considered "brilliant?"

Only move that keeps a winning position
But shouldn't that just be the "best" move? If I recall..the engine only declares moves "brilliant" when it couldn't find the move
There is nothing brilliant about 1… hxg3, which presumably just captured a hanging Knight and is the only move that is not obviously completely losing. The forums are littered with “why is this a brilliant move” thematic threads containing similarly straightforward positions, so I would not give the brilliant move assessment any weight at all. You are correct in calling it the best move.
I've been staring at this for about 10 minutes, can't seem to understand why this is a brilliant move