Why the NBA's Best Defense Lives in Memphis Now

The personnel theory

The Memphis version starts with a frontcourt that is unusually mobile, even by today's standards. Both starting bigs can guard the perimeter for a possession at a time without losing the rim. That sounds like a small thing. It is, mechanically, the thing.

It means there is no exploitable mismatch on a switch. There is, on every perfect possession, simply a different equally-good defender in front of the ball.