Center is interesting. Do you take a year in the mid 60's with Bill, Wilt, Thurmond, Bellamy, Reed, etc.
Or a year in the early mid 90's with Hakeem, Robinson, Shaq, Ewing, Mutumbo, Mourning, Divac, and even very old Moses.
Obviously more teams and thus more options in the 90's, but it seemed like every team in the 60's had a HOF center.