Question on Early Tyson's Jab Mechanics

[BCBUD]

look at how bad his feet are at the end of each clip.

After I studied Tyson for a while, I begin to see many technical "mistakes" in the sense that it all could have been done better, more perfect like Cus demanded. But I guess what worked was the huge element of surprise about his style in general, since most of the opponents simply did not know what to do with it at all

I always thought that he fought like a bantamweight, if that makes sense? As HWs get bigger, they lose mobility and agility, and he fought like a smaller fighter. Like Dempsey.
I don't know if those imperfections were short of what Cus demanded, or just a part of the style. Being squared up like that- on your feet- is a problem to begin with.

Wouldn't he have to square up being the smaller man?