I'm having an interesting discussion (via e-mail) with my friend Jeff, who is a fan of the Texas Rangers. What does it mean to be injury prone? The term is disparaging, so it must have something to do with an athlete's character as well as his or her bodily constitution. Perhaps we can make progress in analyzing the concept by examining paradigm cases of injury-prone athletes. Milton Bradley, who played for the Rangers a year ago and now plays for the Chicago Cubs, is injury prone. Cal Ripken was not.