How come most of the biggest punchers of all time are skinny (gangly) and tall?

I'd replace McClellan and and Jackson, who I don't think were particularly skinny, with Bob Foster and Micheal Spinks and throw Lopez in there as well. Arguello was also quite skinny at 130.

All these guys rank very highly among p4p bangers, It's probably the leverage,

 

I remember when Jesse Benavides came out of the amateurs and was working with yrainers to develop punching power...the guy had studied great punchers training techniques etc...he did improve him but he wasnt a KO puncher. Manny Steward was probably the best in the business for teaching punching but their were some fighters that did not have it...the great Philly wars of the 60s-70s was full of gyms that had punchers absolute animals the sparring was made to bring out the dog in fighters some say that many top fighters left their best in the gym...and you still had guys like Vinnie Curto and Vito Antuofermo who just didnt have power. If you havent been in the ring and felt the different types of power out there it is hard to explain. There are guys who swing for the fences but they have soft fists others have hard hands that feel like rocks some have hard, heavy hands but theough slower others have hard hands and fast punches...some guys are just strong punches not hard....

 

Punchers like Naseem Hamed had powerful legs, so did Marciano & Tua... Gasiev too.. so I don't think it's down to body type, some people just hit hard and some people don't.. I do think you can work on your power somewhat but ultimately you've either got it or u haven't .. I remember a Ukrainian heavyweight called Vladimir Virchis who was a unit, built like a brick **** house yet as soon as he started stepping up he couldn't KO ppl..

 

Virchis couldn't KO people because he was too slow to land on them and had no ring craft. He was powerful though, no doubt.