basically the game auto resign, giving first place 20 points. Whoever has the most points wins at the end, regardless if you got checkmated first. you ended with 41, your opponent had 20, and since they got first they got +20 points, which means they had a total of 40 points.
in the end: yellow = 0, blue = 40, green = 40, red(you) = 41
you got the most points so you win. The point of auto claim is to claim a win by resigning. Ironic i know.
This is the game. My green opponent had so many more pieces than I. Why did I win on autoclaim? Thanks!
https://www.chess.com/variants/4-player-chess/game/28546220/138/1