Kendrick Perkins pushes the envelope

Perkins spoke with me about the craft of setting screens last December before the Celtics faced off against the Bulls in Chicago. I asked him how much a screener should try to get away with:

That's why 29 other teams and their fans would love to have Perkins setting screens for their primary ballhandlers and scorers.

Does Perkins' approach make him a dirty player? Does his strategy make him the ideal heavy in an offense that relies on rotating pick-and-rolls for three perimeter players -- Rajon Rondo, Ray Allen and Paul Pierce -- with vastly different styles and skill sets? Is Perkins' willingness to work the system to the very boundaries of legality help make the Celtics the cutthroat, nasty competitors that they are?