The ankle sprain. If you're a basketball player, you've most likely tweaked your ankle in some way or another in your playing career. For some, the frquency of your sprains gets so bad that you have to stop playing all together or for large periods of time....only to sprain it again as soon as you step back on the court. This is especially true for supinators (those, like myself, who walk on the outside of their feet....only about 2% of the population are true supinators though).
Believe me, I feel your pain (literally...in the summer of '05 I nearly broke my ankle and it still looks like a weird meatball). There's got to be a way to got out this horrible cycle, right? Guess what? The answer doesn't rely on more ice, braces or *gasp* taping! Read over this article by Jimmy Smith, a former college basketball player and nationally recognized trainer.
Doing these drills religiously will not only improve ankle stability and prevent sprains, it will make you a better athlete. Basketball players usually have horrible ankle mobility due to excessive taping, braces, and the dredded Nike Shox (heel lift = bad). Improving ankle mobility will most likely alleviate the pain in that knee that's been nagging you all season.
Ankle mobility will also help you vert. The foot/ankle is the first part of your body that makes contact with the ground as you jump and if your range of motion is limited you won't be able to apply maximum force into the ground. When you load up like a coil to jump, the force you apply to the ground travels from your foot/ankle all the up to your head and back down again before take-off. Basically, you might gain a few easy inches if you work on ankle mobility (don't forget the hips either).