its so hard to say in free for all mate , many have been bitten expecting follow ups that seem winning only to be exasperated that the other players dont play along with the obv best move , so some dont bother taking the opprtunity as 4 player free for all is
"the self preservation society "
I just played FFA game and on move 12, red tries to team with yellow by checking me and Bl6# is mate, but instead of mating me, yellow takes the queen. So red tried to give yellow checkmate, hoping to checkmate blue and win in 2-player endgame? To me it looks like teaming. I want also to mention that blue did nothing to stop mate, my "friend in the opening" betrayed me. Move 26, red resigns and gives blue free points, red could defend by putting the pawn between the king and queen, and after Qxh3+ and Rk2# it's mate, but blue doesn't have to take pawn to give me +20 points, so why did red res? At the end, i blundered 2-3 times and gave blue free checkmate on yellow and get 2nd place because I couldn't think
https://www.chess.com/variants/4-player-chess/game/27949217/144/4