I'll take a stab at an explanation. Watching the slow motion, it didn't really appear to be a jab but more of a right cross where there is a lot more power generated by the shoulder and chest muscles. In addition Liston was moving into the punch, off balance and didn't seem to see it coming. I just watched a video of the full first round in that first round knock out, a minute ago and Ali had hit him with a similar punch earlier in the round. But what do I know about boxing? Nada thing.
I remember at the time Ali claimed it was an "anchor punch" that he had learned from Jack Johnson, presumably by watching film since Johnson died when Ali was 4.
Last edited: Feb 25, 2016