1.7 assist per game for Yao Ming ........ 
even Luc Lonely from 96~98 had a better assist number than that, and Luc played only 20+ minutes per game with fewer turnovers.
number didn't tell you everything, on offense it seems that yao ming does have a decent 1 on 1 game, but on defense he is his teammates' burden. WHY??? YOU ASKED ... well yao ming is just way too tall thus way too SLOW, his lack of speed is the reason why he had high turnovers and got into foul troubles constantly. It has nothing to do with Jeff Van Gundy's game plan, it is Yao's own problem. Patrick Ewing played under Van Gundy's system before and he never had a problem. A good center can play no matter what.
let me just randomly list 10 centers that are better than yao ming
bill russell, wilt, jabbar, bill walton, moses malone, shaq, ewing, olajuwon, david robinson, mourning
so forget about yao vs the dream, when yao ming averges 25/12 in a FULL season let me know.