Knockout Kings is a series of boxing video games that were produced by EA Sports for various platforms yearly between 1998 and 2003. Before releasing the first Knockout Kings, Electronic Arts released its first 3D boxing game, Foes of Ali, for the 3DO Interactive Multiplayer in 1995. While there are a few similarities between the two games, Foes of Ali was developed by a different team, and as such, is not regarded as a precursor. Knockout Kings 2002 changes many concepts of its predecessors, e.g. you have to progress through a number of bouts in order to unlock new fighters.