Knockout Kings is a series of boxing games that were produced by EA Sports for the PlayStation, Nintendo 64, PlayStation 2, Xbox, Game Boy Color and GameCube yearly between 1998 and 2003. Knockout Kings gives the user a chance to compete against 32 real fighters, such as Muhammad Ali, Eric Esch, Marvin Hagler, Sugar Ray Leonard, Oscar De La Hoya, Larry Holmes, Jake LaMotta, Roberto Durán, Alexis Argüello, and Ray Mancini. In the game's "slugfest" mode, fighters can knock each other out at any given moment of the fight, or suffer 6 or 7 knockdowns and still last for the whole fight. There are several differences between Knockout Kings and real-life boxing careers. Championship bouts are only for 10 rounds and not for 12 as in real life. In the career mode of Knockout Kings, a fighter is made to retire right after winning the title and defending it for only the first time. Also, Knockout Kings does not have women's boxing. The exception being the PlayStation and the PlayStation 2 versions of Knockout Kings 2001. Before releasing Knockout Kings, Electronic Arts released its first 3D boxing game, Foes of Ali, for the 3DO in 1995. While there are a few similarities between the two games, Foes of Ali was developed by a different team, Gray Matter and as such, is not regarded as a true prequel. After Knockout Kings 2003, the series was canceled and replaced by Fight Night 2004.