It's not like Tim Duncan changed his game to become more of a center than a power forward...rather, the league has changed to become more small-ball dominant. Besides, Duncan's prime were in his power forward days.
In 1997-2003, Robinson was clearly the center. Backup was Will Perdue, Kevin Willis.
In 2003-2006, Nesterovic was clearly the center. Backups were Kevin Willis, Nazr Mohammed.
In 2006-2009, Oberto was the center.
And now in 2013/14, Tiago is getting the nod.
So I ask: why was Duncan listed at the C on BBallreference? I watched the games, saw the starting lineups...and no way was Duncan playing the C in some of those Playoffs.
Duncan played PF in the era when it was fashionable to have two 7-footers on the floor at all times. Now, in an era with smaller players in general, he plays center when Splitter is gone.. Overall, he is a forward-center. It's that simple.
There aren't even any positions anyway. There are frontcourt and backcourt players, as well as wings. Duncan's skillset is so interchangable that he could play both positions...but he spent most of his years, and his best ones, at the PF.
According to Basketball reference, Dirk Nowitzki played Center in both 02 and 04.
Andrea Bargnani has more seasons playing Center (11, 12, and 14) than probably some actual centers.
Al Horford despite having PF abilities and skillset has never played PF according to BBR.
DeJuan Blair started 250+ games for the Spurs and is more of a natural center than Tim (Blair was a collegiate center, has no jump shot at all, and is predominantly a post player) has never played center according to BBR.
Mehmet Okur played 5+ seasons of "center" despite hovering by the 3 point line and launching hundreds of 3's.
People are quick to label Anthony Davis a PF despite Tim in his physical prime having way more of an offensive repertoire and midrange game.
Positions aren't always black and white, and today's league is in love with the Kevin Loves, big men who live at the three point line.