Speaking of the headbutt, or butt punch, here's an article from Cleveland.com:
Boxing Insider: Pavlik prepares diligently
by From staff reports
Monday October 13, 2008, 8:33 AM
Associated Press
Kelly Pavlik celebrates his win over Bernard Hopkins.Kelly Pavlik has covered all his bases.
As the middleweight champion closes in on Saturday's nontitle match against Bernard Hopkins in Atlantic City, N.J., the Youngstown fighter has also gone out of his way to protect his, well, dignity. Pavlik and trainer Jack Loew brought in sparring partners Zack Page, James Countryman and Byron Mitchell, the latter a pretty good lookalike for the veteran Hopkins (48-5-1, 32 KOs).
Team Pavlik expects Hopkins to pull out all his veteran tricks, especially early, to stymie Pavlik and get him off the offensive.
"I've always been compared to Hopkins," said Mitchell (25-4-1, 18 KOs), a two-time super middleweight champion from Ozark, Ala. "Kelly is a lot stronger than he looks. I've tried some of those tricks."
Mitchell said hitting in the clinch, banging on the thigh, bumping with the shoulders and elbows, along with slamming Pavlik in the butt are just some of the tactics to be expected.
"You can prepare for that," said Pavlik (34-0, 30 KOs). "First we come to fight. Then we'll deal with that other stuff."