McGregor is regarded as one of MMA’s hardest punchers, but in his fight against Mayweather, Floyd never came close to being hurt, and managed to knock Conor out. Floyd has been hurt against fellow boxers like Mosley and Maidana, but took Conor’s punches just fine.
Do boxers hit harder than MMA fighters, or do they just have better chins?
I’m not an expert in either, but I think you’re discounting a more likely explanation. Mayweather wasn’t hurt because he wasn’t really hit the entire match. If it was just a static face punching contest you’d have a better comparison.
A trained heavyweight boxer can deliver a punch with over 1000 ft lbs of force. A Karate reverse punch can deliver about half of that. Boxers also build up neck and shoulder muscles to help absorb punches to the head.
This is why most MMA fghters punch like boxers and train in boxing rather than traditional Karate punching.
It’s the old story of a generalist (MMA) vs a specialist (boxing). Any time you have that situation you’re going to have the specialist better at the one thing they do than the generalist. But the specialist is going to be so much worse at things outside his speciality.
Look at baseball. A designated hitter will be great at batting but can’t field very well. A fielder can field well and might be good at batting but not as good as the DH. A pitcher is okay at fielding, a joke at hitting, but can pitch very well which the non-pitchers can’t do.
If you train with a focus the end result should be predictable.
McGregor can deliver a punch, but there are differences in boxing and MMA that I don’t have time to get into. In a boxing ring, with boxing gloves, with boxing rules, McGregor looked weak against a great professional boxer.
In MMA rules, in an octagon, and with five ounce gloves, McGregor would teach boxers a thing or two even if the fight never went to the ground. In a boxing ring, Mayweather ruled the evening. But make no mistake: in an MMA match, or even out in the street, McGregor would show Mayweather what kind of punching power he has.