How many true NBA centers are there anymore? The definition of the position has totally changed from what it used to be. We look at a guy like Dwight Howard, the best Center in the league... and he'd probably be playing PF in the late 90s because he has absolutely no post moves, not to mention that he's the same size and build as Karl Malone. That's what the league's best C looks like now. The whole point is that if you use the model of the Spurs and Heatles from the last 3 years, the 4 is a spread player and the 5 can be undersized without being any liability. Since the top 3 bigmen on the Celtics are all spread and undersized, why wouldnt they be interchangeable.