Ironbear24
Senior Master
Who? I have never once heard a serious martial artist make that claim. I've heard people say that technique matters more than weight, or that lighter people have certain advantages to minimize their disadvantages(hear that one sometimes when talking to grappling friends), but I've never heard anyone deny that it has an effect.
I hear it all the time. You never hear of the age old romanticized tale of how the 5'2 100 pound old Asian men could beat people twice their size?
It is so beaten into the minds of people that many thin guys get cocky and even trash talk big dudes. Saying things like pfft I'll dance around you until you tire out. Honestly a fight like that could go any which way, it all depends on the two individuals experience.
Size however does matter, if it didn't we wouldn't have weight classes in combat sports. It's why bigger guys have to be careful when sparring with smaller guys and it's why I accidentally hurt someone, becuase I have a hard time controlling how much force I use.