All that Matters is Speed for Chinese Kung Fu

Look at this Picture I got from the website, what I estimated is that Bruce Lee was about 5' 8" tall and about 148 Pound in weight, and he is even about 2 " taller than Ip Man. So Ip Man was about 5' 6" and total weight of about 143 pounds. How can this tiny man could be one of the best Kung Fu Fligther in the 40's Well, All I think is the speed, Brice Lee could catch a dropping knife with the same hand, and he could made a side kick and sent a 180 pound-man 20 feet away,... That was what I saw in the US TV series about a blind police investigator..in the 70s'
So when we practise, we had to move at the highest speed we can... so call Lee's Invisible Kick, because it is just too fast to be seen...
HK Snob