Why was this move brilliant?

Hello,

I'd like to know more about chess.com algorithm. Today i got my 2nd brilliant move and i really wonder why was it so?

I had a tough game (At my begginer level ) and i barley managed to squeeze out a draw by repetition but i wouldn't go as far as to call it brilliant. 

Was there a line i fail to see or is it simply for forcing a draw in a lost material position?

Btw, please ignore that bishop e3 blunder  My thinking was Qc5 to Qe3 later on but obviously it didn't work out

38. Rd2± :)

When his king moves d1-c1 after your brilliant move.

Rd2-f2, the king does not have time to get back and prevent the oncoming checkmate when Rg2-g1.

His rook can't prevent that checkmate in any way, he can't move his king to prevent it, can't move any pawns to prevent it, the only thing he can do is check your king with his queen and he only has one square to check on.

So after Rd2-f2

Qe7-e8+

Kg6-g5

Qe8-g8+ (again the only sqaure the queen can check on since the pawn covers e5)

Kg5-f4

Qg8-b8+ (again the only square that queen can check on, the only other option is capturing the rook on g2 but blacks rook on f2 would recapture.

Kf4-f3

When the king is on f3 the white queen can't check it in any other way and it still can't prevent the rook from going to g1 for the checkmate, even if queen captures the pawn on a7 to get the diagonal line towards that square the rook is still being covered by the other rook on f2 so it won't matter.

White can't do anything to get out of it and black wins.

Nah Rb5 is better than Qg8

and white wins

the best move is to perpetual check and draw

The only explanation for that move is your computer is on drugs

You're right I didn't see rb5, he would then be able to check again on f5 and trade rooks, damn, nevermind everything I wrote ha.

As far as I can tell, "brilliant" means "better than the computer's first thought."  The computer runs very briefly and picks a "best move."  If your move is better than that, it's brilliant.

It's a nice reminder to be very skeptical of the computer analysis on this site; the computer is not running long enough to be reliable.  (You can see this on the analysis board if you follow down the lines it gives, making its "best move" each time; sometimes those "best moves" are actually quite bad and it will realize this down the road!)

+1

I actually do not believe the computer can miss a move in the middle of a perpetual check and find genius sacrifices that wins and call it best moves

lc0 has lost to a human.

I cuaght someone with exactly the same combination today.

Thanks guys.

I have also found out something curious today. I ran a report on the same game again and there was no brilliant move this time.

Perhaps the computer is a fast learner

Eh how does that reply to my sentence

I said that I do not believe that:

the computer will see a queen sac followed by multiple pawn sacs and some pieces sac checkmate in an instant

but

did not see a perpetual check of 2 rooks

damn puters