There is talk about his famed punching power but when I checked his page on Boxrec and he has 33 KO's out of 86 fights. https://boxrec.com/en/proboxer/12440 Is his punching power overrated or is there a logical explanation behind this?
There could be many reasons. For example... Maybe he hit so hard that the guys he fought changed their approach against him. Maybe they moved more than usual or tied up when he got in range. Maybe the guys he fought knew how to fight, how to switch angles, how to smother shots.
He was basically the Shavers of his era. He might have hit harder than Louis, or even Baer, but he didn't have much outside of power.
Archie Moore said something like "every time he landed a punch, he knocked me down" (probably an exaggeration...), but Arch made sure he didn't land very often.
Remember their being a article on Moore in a old Ring mag, many, many, years ago, he stated that Sheppard had hit him harder than both Charles @ Marciano !!! also that he was one of 2 fighters that gave him the most problems, the other being Burley, of whom he said was " slick as lard, and twice as greasy " there you have it.