Well, he has 14 KO's in 18 Wins. 77.778% KO But to be fair, Kirk "The Movie Star" Douglas seemed...less than willing to fight. Might have chose not to get up.
Yeah, I know his KO percentage is high. I've just seen him fight a time or two and he didn't seem that impressive. Maybe I'm just expecting his dad.
As far as impact, the shot Ali hit Liston with in the second fight. To this day a lot of people say there was no punch. To my eyes, Liston got hit right on the point of the chin when Ali was full of energy. Some of the ring siders say it lifted him off his feet. People will probably argue about that one forever.