What's the difference between the best move, a great move, and brilliant move?

Best, great and brilliant are all best moves, but best is just BEST, and great is when there is the only move that works, and a brilliant is something like a good sacrifice

Best: Exactly what it sounds like.

Great (!): The only good/reasonable move in any given position. Note that the move in question must actually be good. If all of your legal moves suck (zugzwang), but one in particular sucks less, it probably won't get a "great" rating.

Brilliant (!!): A move that sacrifices a piece or ignores a threat on one; however, no matter what your opponent does, it's their position that will worsen.

The engine doing the "Game review" is shallow and dumb. It can't be trusted. The "mistake and miss" were actually good moves.

Also. don't cheat.

There's still time to delete this. You're gonna get banned anyway.

You said "Great (!): The only good/reasonable move in any given position. Note that the move in question must actually be good."

I got a Great move in this game:

https://www.chess.com/analysis/game/pgn/12rWxj3WkN?tab=review&move=24

In this position I played Bh6+. However Nxc6 was either equally good or better. When I tried that move instead it gives this move a "best move". On Chessly.com Nxc6 is considered the top move.

Thoughts?

It's no surprise that different engines at different depths of analysis consider different moves as best.

But chess.com labeling Bh6+ as a "great move" is clearly a bug. It goes against their own definition of the term.

Also I noticed that Game Review Guy is talking complete nonsense about losing a queen with a fork. This isn't a surprise either, Game Review is just beyond awful.

I think a great move is either the only move or gets a huge advantage like taking a queen or horse. Tell me if I'm wrong. Error 9999999999

did a 2 brilliant moves today !

My response after over 1 year: best move is the best move in a position. Great move is possible when: 1) You found the only move that is good in a position, it can be advantageous for you, or just the only move that keeps the position equal. 2) Also can be just a tactic, like an exceptional fork that brings victory to the home, or something else. 3) A brilliant move is when you make a good sacrifice of a piece. It doesn't count as brilliant when you have an absolutely advantageous position, like much more material than your opponent has. It counts as brilliant when you sacrifice a piece to keep your advantage, and the material that you and your opponent have is equal. That's all

Also it's important to note that the condition for you to get a great move or a brilliant move gets harder when you have more rating. For example, if you are low rated, just taking a hanging piece can be a great move, but in my rating it is much harder, and when I take a hanging piece, it is just best move, not a great one

I don't think anyone clearly knows this.

Brilliant moves aren’t just sacrificing a piece, they can also be a surprising attack that’s surprises your opponent, or a smart trick that catches your opponent off guard

for example, one of my games in my game history had a brilliant move because i IGNORED a big threat on my bishop, and came back with a very strong response

If you leave a piece to be captured, that's also a sacrifice.

On chess.com, brilliant moves are sacrifices. That's the definition they use. No exceptions.

best moves are the top engine move

great moves are usually the only good move in the position that doesn't force a draw or lose

brilliant is a sacrifice for great compensation or the only move in the position that isn't completely losing for you

"brilliant is a sacrifice " - so far it is true.

The rest of your sentence isn't.

The best move is the best move in the position. A great move is the only good move in the position. A brilliant move always would change its meaning on chess.com, but now it means an amazing sacrifice