Today on Khan Academy there was a Probability tutorial (http://www.khanacademy.org/math/probability/v/lebron-asks-about-the-chances-of-making-10-free-throws tutorial) on how to figure out the likelihood of a given player making 10 consecutive free-throws.
Apparently Lebron's career FT% is right around 75%. A great free-throw shooter like Chauncey Billups is just short of 90% for his career, while Shaq and Ben Wallace can shoot as low as 40% to 50%.
Are free-throws something that NBA players spend a considerable amount of time practicing? And if they do practice a lot, does their FT% tend to reflect that and get higher over the course of their career?