Is a great move better than a best move?

I don't know the difference between a great move and a best move. Is there a difference and if there is what's the difference?

Great is "hard to find" and better. Brilliant is the best.

These are both essentially meaningless adjectives, assigned by some computer algorithm. Moves are good or bad, strong or weak, And remember: 40 "great" moves, followed by one big blunder equals a loss!

So is there a difference?

So, from my understanding the best move is the best move based on the evaluation from the engine and a great move is like a "critical" move where it must be played in order to continue to either stay ahead or grab the advantage.

I dont like the labeling of "great" move because many times it's just a standard must play move. 

It makes little sense.
Objectively there are only good moves, mistakes (?), and blunders (??).
A good move does not change the game state draw/won/lost.
A mistake (?) changes the game state from draw to lost or from won back to draw i.e. missed win.
A blunder (??) changes the game state from won to lost.

This whole "great." "brilliant," "best," "hard to fine" nonsense is just that--nonsense! Moves are good or bad, strong or weak. Any time spent worrying about what adjective a computer algorithm assigns to your moves is time that you could spend studying chess and getting better. These terms are just sucker bait 

The actual information can be found here:

https://support.chess.com/article/2965-how-are-moves-classified-what-is-a-blunder-or-brilliant-and-etc

To answer your specific question regarding the difference between a best move and a great move. A best move is technically the best move but might not have a significant impact on the game. In many positions the second best or third best are evaluated almost equally. There can be 5 to 6 playable moves that all result in roughly the same evaluation. If you adjust the engine depth setting from depth 18 to depth 20 the move order might change immediately.

A great move on the other hand does have a significant impact on the game . In many case it can be the only move that doesn't lose the game on the spot. 

Let me share an example 

I got a "great move" today because I played the only move that doesn't end up trapping my bishop 3 moves later. It wasn't a great move at all it was the obvious move where any other move would have been a mistake. 

Take this whole "great" label lightly, the moves aren't that great. Should change it back to "critical move"

Don't take chess.com's engine analysis too seriously. 

Yeah, if you want to get better, this analysis won't help as much as you think. I've had so many games with awful analysis. Half the time the "best move" doesn't even line up with the engine.

Analyze your own games with a good engine, or have them analyzed by someone else.

That's a shame. I was under the impression the analyses here wasn't to bad. At least not for beginners like me.

I thought Stockfish was a good engine. Maybe it would help to set it on a deeper mode?

That's the standard setting, but you can enhance it…

The deeper you make the depth the better results you'll get. That's one of the problems. Diamond members get a pretty good analysis with the max depth. Not sure what you can do at your membership, but increasing the game review depth will give you much better results (though it will take longer to run). In my opinion, it's worth the wait.

Stockfish is one of the best engines out there, but with any engine, results improve with more depth. I've played around with chess engine development and that is one of the biggest things that improve performance. 

I'll also say for beginners the analysis is not that bad. The new game review feature is pretty neat and could be helpful. I'd recommend, if you can, to use the game review on all your serious games. Do not, however, only go by what the site claims is the best move or a blunder alone. Use the engine in addition unless you're using the "re-try mistakes" feature. 

It's also nice to utilize engines in your browser without having to download a program anymore, but that comes at the cost of having to pay for better analysis which is my biggest issue with the analysis here especially when there are so many free engines out there that can perform better analysis for free. The only thing you give up is the game review feature, but if you can do simple math and if you know how the engine "thinks" and displays results you can annotate your own game with "!","?!", etc. which is what I do.

Basically, if you're not paying full price for max analysis the engine is pretty bad, and to be honest $99 a year for the engine is too much anyways.

For me, as a Platinum member it looks like this:

I know there are other ways for analysing your game, online or on my desktop with Scid vs Pc. I think I'll  continue to use the in-build feature here at chess.com for its nice interface and replay function for the first glance. Of course I don't trust it blindfolded, if I find out the engine here is not helping, I can always choose another option.

20 is good for a simple run-through of your game, but personally, I'd throw it to 99 and it'll just keep running as I'm looking at the position. The time is just the time it takes to reach that depth, it doesn't mean if you take the move before the time limit it won't be good, it just hasn't hit the depth you set. 

I set my lines at 3 because its enough to see other options or the move that you played, and it shouldn't slow down your computer too much.

Game review on the other hand will run to the depth you set on every single move so changing that would take longer to get your results back and I'm not even sure if this site allows that kind of intensive analysis. The cool feature here is it will run the entire game for you first and then you can look at it, but keep the engine on when going through games anyways because it'll run a better analysis. 

I enjoy changing the engine from Stockfish 12 every now and then, but if you just play around with all these settings you'll find what works for you once you factor in time, and required computer power

The game analysis is on this site is great. I always go over the analysis after a game. (as an extra tip: I've creates two libraries called "study later black" and "study later white" so I can review them when I have time). For more in depth analysis I use Stockfish 14 that's available for free.

Stockfish as an engine is absolutely fine.. You just need to be aware of it's limitations and appreciate the output for what it is. Stockfish is great for spotting your own mistakes and blunders, especially where tactics are involved. 

However, a couple of things to keep in mind.

• Early game engine analysis can be very unreliable, for multiple reasons
  • not all available moves are considered 
  • Depth 18 (9 moves) is not deep enough to take into account positional (dis)advantage
  • Calculating best play for both sides in this stage is not realistic
• Engines might suggest a best move that's highly unpractical for humans
  • A move is best assuming a certain continuation. It won't be good if you don't know how it will benefit you later in the games. You won't get the payoff.
  • t evaluates a position based on playing the perfect move, move after move. It can suggest something no human would feel comfortable playing. The inverse is also true: an incredible move at the 1200 rating level might get a low evaluation because the engine has found a way to counter it

how can 'great' be better than 'best?' best is by definition...best.

A great move is better than the best move and lucky people and smart people only gets great move or brilliant and 1 time I got a great move but the best is Brillant...

That doesn't make sense to me. If you're threatened with a checkmate in two and have only one square to move with your king, no other defences possible, moving your king to that square would be the "best" move. But that wouldn't be great or brilliant. 

you don't understand