The science of punch resistance

This. Pacquiao had a medicore chin as a whippersnapper and a relatively mediocre chin as he moved into the decline phase of his career. But there was a solid 5+ year stretch where it was cast iron. It takes a certain caliber of chin to walk through Marquez.

 

Neck strength and vision/anticipation are the key elements. Strong neck and the ability to see and/or anticipate what’s coming is the key.

 

When did his chin start to decline?

 

Sometime after the Margarito fight. Pac was physically never the same fighter after that. 16 years pro, countless wars and having a massive Welterweight bang on your ribs when you're nothing but a blown up 126-130 pounder will do that.

 

Spot on assessment. I would add that a boxers physiognomy is also crucial for punch resistance. A pronounced chin and non recessed jaw/maxilla is paramount.

 

He does, but are his reflexes RJJ, Judah, Khan level? I guess that's up for debate. Again, my observation is just that an observation. No scientific data to support it.

 

It's more about anticipation than reaction for Canelo. Guys like Baldomir, Mosley, and Cotto showed him all the tricks at 80% speed while Floyd, GGG, and Lara were more complete tests.

No one else really has experience like that at the pro level right now.

High level experience matters!

 

This has always fascinated me as a topic and, unlike punching power/effectiveness imo, elite level chins (ability to take a punch well) is purely genetic.
I'm talking about the Haglers, Chuvalos, McCalls, Frochs, GGGs and LaMottas of the world. I believe that conditioning plays a big role also, but, there's simply no way that anyone can train their way to Chuvalo level chinnery.
Whether it's through bone size/density, joint leverage, brain cushioning, or a combination of all these and more, I think that "chin" is the most unfair part of elite level boxing and, more so than any other attribute, you just have it or you don't.

 

Neck muscles. Bone Structure. Skull shape. Hormones and adrenaline levels. Psychological factors such as general hard-arse-ness, upbringing. Technique including leg position, head and punch mitigation skillls.

 

One thing that helps CA is his ability to roll with punches. He does that very well.