Jefferson can body up at C similar to BBD and Shaq (similar, not exactly the same) and he's big enough that when he plays PF his help D isn't terrible. But he's generally a bad defender. McHale was a great defender. That's why Jefferson isn't a star (and playing mostly on bad teams during his career.) Stars play both ways or handle the ball a lot on offense (think Steve Nash). I'll be interested to see if playing for Sloan gets Jefferson to defend better, the way playing in Doc/Thibs system seems to have brought the best out of Ray Allen (not known for D his career until he came to the C's.)