While you do make a solid point, Mirko's younger and still has some fight left in him, plus if I'm not mistaken, Kick-boxing gloves are thicker, so your fist is more covered causing punches to be less effective and KO's to be harder to come by.
If you asked me, I'd probably say Chuck's chin is a lot more faded, being that his losses were more devasting. Maybe Mirko's last 3 MMA fights were KO losses, but he was still able to put up a fight for 3 rounds. With Chuck Liddell, you're talking about someone who couldn't even make it out of the first round in his last two fights. That would lead me to think that If he were to fight again, he probably wouldn't last half a round.
K1 has some kind of absurd KO percentage like 85 or 90%. And there have been quite a few studies that show the thickness of the glove has little to do with actual punching power. Gloves protect the hands not the opponent. If I had to guess I would say it's because mirko doesn't have to worry about being taken down so his whole game changes.
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