Ben Wallace - Wikipedia, the free encyclopedia:

"Like other big men in the NBA, namely Shaquille O'Neal and Wilt Chamberlain, Wallace is a poor free throw shooter. In fact, he is the worst free throw shooter in NBA history out of any player with more than 1000 attempts. As of October 2005, his NBA career average is 42.0%. This ineptitude at the free throw line results in his sometimes becoming a target of the so-called 'Hack-a-Shaq' defense (A tactic that has drawn the ire of teammate Rasheed Wallace). The reason for this drawback is that his right wrist has some ligaments that were cut off due to a surgery that was needed because his hand had some carpal tunnel issues. This causes his hand to go 'dead' whenever he dunks, falls to the ground, or when he shoots a free throw, resulting in him being unable to make them on a consistent basis."

we finally know why he can't shoot free throws...