Center is one of the most decorated positions, sure, but once again the problem is defining what makes player X better or worse than player Y. Tracy Mcgrady at his peak was better than Ray Allen, but Ray Allen had a better overall career. Do we give Russell credit for sacrificing his own stats for the sake of his team?
I tend to fixate on "impact" which I admit is fairly nebulous itself. I also like to distinguish a player's peak performance from his overall performance. For example, D Rose before the injuries was a top 3 PG easily. Base on "peak performance" and "impact" Shaq from 99 to 2003 was possibly even more valuable than Jordan
I go mostly by impact and longevity. Shaq played with Penny, Eddie and Nick, Kobe, Rice, Wade, Pierce, STAT, Allen, LeBron (probably leaving someone out, damn near forgot Bron
