That is by design. The site determines that the player's rating at the game conclusion is the more accurate of the two ratings, so it uses that.
Broken "Best Win" Stat
Sort:
I understand that but I wonder if common sense agrees with this determination. Suppose you challenge world's champion and he losses, and he is no longer a champ. Would you say you have defeated world's champion or world's ex-champion, 
. When you start the game -- one player has rating X and another rating Y. So it is really a game where X plays vs Y. If you win -- it is really X rated player won Y rated one, and only AFTER everything is over X becomes X+n and Y becomes Y-n. Why would site determine that you have defeated Y-n rated player when before the very last move it was really a Y rated one?
My question is, how is the "best win" statistic calculated? What is the formula?
Nov 6, 2017
0
#5
Best win is the highest rated opponent you score a win against, based on the rating after your game is completed.
Though, it looks like it may have changed to a certain time frame or it is bugged out because I don't have any showing
Sep 4, 2023
0
#7
To say it is "by design" or "this is the more accurate rating" is kind of BS. You won against the player when he had a specific rating and not the new one he had. By that logic, if that person kept on losing rating then your best win should also change, which does not make sense really. If you beat a 1800 player then you beat a 1800 player, not a 1793 player...
Being a software developer, I can guess with great confidence that the reason is probably convenience of the code, since even in the game's info you would only find the new rating and not the old one, if you wish to get the old one it requires a bit more coding work to change the game info to hold the old rating as well.
So basically, a bug by design due to lazyness.
Yes, the "Best Win" Stat is broken. If you win against a player who had a higher rating than any of your opponents before that win -- the stat will show your victim's new rating as your achievement, i.e. his rating AFTER he lost to you. Not the one he had before you challenged him, but the one which was brought down thanks to your win. I am sure somebody had to notice it before, the question is why it was not fixed by now?