Alex Rodriguez, who’s arguably the greatest player of his generation, has done a poor job of maintaining a clean reputation. After admitting to steroid use, receiving the nickname "A-Fraud" from his teammates, cheating on his wife, and enduring the perception that he’s "unclutch," he’s made things even worse by participating in illegal high-stakes poker games. Of course, plenty of athletes have tarnished their reputations and careers due to their penchants for gambling. Conspiracy theorists, for example, like to claim that Michael Jordan’s first retirement was "forced" by David Stern because MJ allowed things to spiral out of control. The sometimes shady activities of these ultra-competitive, testosterone-laden jocks can produce fascinating stories. Here are 10 guys who serve as proof.