Marciano is the man yer looking for. Who pushes and ducks below their opponent's belt line? Not to mention the rabbits, low blows, and late hits.
Whether or not it's written in the rules the fact is you can't push. However if you are up against a guy who is trying to clinch it is fine to push him off. I'm not saying Peterson was trying to hold. He was just trying to work in close to Khan where he had a better chance of winning. The fact is pushing is an extremely minor foul and that ref has got to be kidding to take a point let alone two. Khan's pushing was excessive but I have never seen a point deducted for pushing. Holding is a more serious offense and you rarely see anyone punished for holding. Khan was hard done by in that fight. Even though he lost 2 points he still won 8 rounds so he was shafted by the ref judges and Peterson who tested positive. He had good reason to ***** about what happened in that fight.