In each of Russell's 13 seasons, Boston's defensive rating was dramatically better than the league average. And that elite defense anchored by Russell led to 11 championships in 13 years. In many ways, he's the perfect answer to this question, because defense is about so much more than numbers. They can never truly measure communication, rotations and all the things an offense can't do because of it. Even if they'd existed, the greatest defender of all time would've transcended the numbers and accolades anyway.