Kingmaker scenario

In game theory, a kingmaker scenario in a game of three or more players is an endgame situation where a player who is unable to win has the capacity to determine which player among others will win. This player is referred to as the kingmaker or spoiler. No longer playing for themselves, they may make game decisions to favor a player who played more favorably (to them) earlier in the game. Except in games where interpersonal politics, by design, play a decisive role, this is undesirable.