Who are the top-10 centers in the game? Are there even enough worthy centers to compile such a list?
Some say there's a dearth at the center position right now, so would answer no. I disagree. I think it's a change in the way the game is being playing that has changed what we need to look at and understand what we want from the center.
Certainly we see less scoring form the center position than we did 20 years ago. In the 1992-93 season there were six centers who averaged over 20 points per game. In the 2012-13 season there are none.
Changes in the game have forced teams to reconsider how they use centers. Changes like the initiation of the defensive three-second rules have forced centers to play defensively further away form the rim, in turn shifting the responsibility for scoring to the perimeter players.
In fact in the last 10 years, since the rule changes designed to do that have gone into place, there have only been 11 player-seasons of at least 20 points per game by only four centers, Shaquille O'Neal, Yao Ming, Dwight Howard and Brook Lopez.
What's happened is that we still measure centers in the same manner we used to though, rather than looking at them according to what the new-age center is expected to do. While there are still some conventional centers (Andrew Bynum for example) the majority are expected to score less and do other things more.
The new style of center is expected to be able to defend the perimeter, hit jumpers on pick-and-pops, pass the ball, set effective screens and still do the rebounding centers have always been expected to do.
Some centers are purely the old-school centers, such as Andrew Bynum. Some, such as Marc Gasol have elements of both styles to their games. Others, such as Joakim Noah are purely the new breed. Consideration was taken into how well they played their role, not just how well they performed traditional center duties.