Ali is overrated mostly by his hook ratings (20 Right, 17 Left), but I've seen decisions where Tyson has gotten questionable favorable calls.
This from an earlier post by me:
Interesting scoring sometimes. I lost a fight because they gave Tyson (my opponent) the first even though I outpunched him 35-23, and outpercetaged him 35-67 (52%)-23-91 (25%). I had the edge in power punches (non-jabs not power modified) 22-21.
No stuns in that round either.