Michael Jordan -- '88 Dunk Contest Was RIGGED ... Says ESPN's 'Sports Guy'

Michael Jordan should NOT have won the '88 Slam Dunk contest -- and only emerged victorious because the whole thing was RIGGED ... so says ESPN's Bill Simmons.

The Sports Guy was in L.A. for the ESPYs when our photog asked the notorious basketball junkie who'd win a current day (and nearly geriatric) dunk-off between MJ and Dominique Wilkins -- a rematch of the '88 final.

Bill's response is near blasphemy to anyone from Chicago (as our camera guy is) 'cause not only does he pick the Human Highlight Reel ... he also claims the original battle was a total sham.

There's more ... Simmons also explains why LeBron and Blake Griffin will NEVER go head-to-head in a dunk contest ... no matter how much money people try to throw at them.

Meantime, check out the '88 footage ... does Simmons have a point?