Before he became a sideshow, Dennis Rodman was one of the best rebounders in NBA history.

He won seven-straight rebounding titles from 1991 to 1997. He's the only player to average 16 rebounds per game since 1979, and he did it five times. He was a better rebounder than Shaq or Dwight Howard in their primes.

This great anecdote from Isiah Thomas, who was Rodman's teammate on the Pistons during some of his best years, gives you an idea of why he was so productive.

Thomas says Rodman has genius-level basketball IQ, and he'd count the rotations of the ball to predict where the rebound would go.

The anecdote comes from a 2011 Jo-Ann Barnes article in the Detroit Free Press, and it popped up on Reddit this morning:

"We were standing in the lay-up line, warming up and shooting, and Rodman was standing back and watching everybody shoot. I said, ‘Hey, come on, you have to participate; everybody’s shooting lay-ups, you have to shoot lay-ups, too.’ And he said, ‘I’m just watching the rotations on the basketball.’ I said, ‘Excuse me?’ He said, ‘Like, when you shoot, your ball spins three times in the air. Joe’s sometimes has 3 1/2 or four times.’

"That’s how far Rodman had taken rebounding, to a totally different level, like off the charts. He knew the rotation of every person that shot on our team — if it spins sideways, where it would bounce, how often it would bounce left or right. He had rebounding down to a science, and I never heard anyone think or talk about rebounding and defense the way he could break it down.

"When you talk about basketball IQ, I’d put Rodman at a genius level."

What's even more amazing is that Rodman put up those historic rebounding numbers despite being just 6'7".

He has been marginalized as a basketball player because of his off-the-court behavior. This is a reminder of just how good he was.