This paper extends Beviá and Corchón (2013) to a model with both endogenous contestable prize and endogenous relative strength. Such a setting is ideal for the study of intra-organizational rivalries, commonly observed in family, sports, promotion, and duopoly. We find that when the game starts with asymmetric players, the weaker player exerts more effort than the stronger player. As a result, the weaker player partially overcomes the disadvantage of being weak. In this setting, neither domino nor avalanche effect exists.