Which Non-Combat Sport has Athletes with the Most Potential in Boxing?

Just looking for opinions. Let's see: American Football: I'd guess most would gas out FAST due to their physiques. Soccer/Fùtbol: Stamina, check. Footspeed, check. Power? Chin? Ring IQ? Questionable. Tennis: Same as above except possibly better Footwork, and less stamina. Basketball: Same as above, but tall guys who can box at range could possibly do well. Baseball: Power? Accuracy? Check. -but can they use it effectively in the ring? Hockey: Some tough MFers who love to fight, good balance, who knows? Rugby: Same as above except maybe the balance part.. Golf/Poker/etc: Are these really sports? Skateboarding: Interesting idea to me. The pros here have insane footspeed/coordination/balance/stamina/etc. No fear. No strangers to pain, all have suffered many broken bones (legs, arms, ankles, wrists, etc.). Only question would be power and chin and of course Ring IQ (for all). Also, most are heavily built in the legs and not top heavy. http://3.bp.blogspot.com/-3HDld8S0XpU/Uhu1kmeF3iI/AAAAAAAADJc/xqsgRMobTIo/s640/truco.gif Can you catch everything that just happened there? Obviously there are levels to Boxing. I'm just wondering which other Sport has Athletes that could have potentially done well if they were trained from an early age.