I have no idea about the bona fides of Marciano's test,or how to translate that into quantifiable power. So I neither discount it or endorse it. I think he probably hit as hard as any man under 190lbs ever has. As far as I am aware only one man of any class named Marciano as the hardest single shot puncher they ever met,that man being Walcott. Lastarza,Cockell,Charles,Moore , Louis, all named other men as having hit them harder . No I have never seen anyone actually make a practical attempt to debunk Rocky's test. I have seen many posters scoff at it,but whether they have any justification for their scepticism or not I do not know. Again that is not conclusive,the best we can say imo ,is that Marciano was a tremendous puncher for his size akin to Langford,and Fitzsimmons. If say,Satterfield had taken the same test as Rocky ,under the same conditions ,it would not have surprised me to see him achieve similar results.
I personally think Satterfield is the hardest puncher under 190. The other men are all close I’d assume. Splitting hairs. But man can they bang.
Fitz, Langford, Goddard, Dempsey and Braddock are the big 5 with Schreck, Bill Lang, Patterson, Marciano being another grouping. Besides Fitz everyone here had more power weighing above 190 obviously. Jack Root is a dark horse to consider here. How much he weighed during the Russell fight is unknown. But being around the LHW limit knocking 6 ft 3 guys down suggests he would have had exceptional power at 190 even if its mostly hypothetical. Choynski at 170 couldn't handle Russell it was a bridge too far for him. If we're looking at LHWs Qawi, Beterbiev and Wild Bill Hanrahan are in the discussion for sure. I added Dempsey to my big 4 because I didn't realize he was under 190 until the Firpo fight.
Choynski beat Russell on a DSQ. Lang ,Schreck,and Braddock were decent punchers, but nothing exceptional.
managed to KD Usyk in the amateurs, and Yarde is bigger than most of the dudes the other names fought after rehydrating.
Per boxing rec "Blinded by blood from cuts over both eyes, Russell knocked out Choynski after the bell and was disqualified. The fight had been a rough one throughout, both men being thrown to the canvas more than once. Joe was out cold for more than 5 minutes." For a 190 guy Langs power was exceptional. Hes really the standard for 6 ft 1 190 guy with power. He wasn't that great a fighter technically and thats exactly the point that punch carried him. Opposed to someone like Patterson. In terms of guys who could hit hard below well below 190 Schreck is near the top of the list. Besides Louis and the Baer bros Braddock probably hit the hardest of the HW champs of the period between Dempsey and Liston and he might have hit as hard as them at over 200. The thing with Braddock is he was only at 190ish for a few fights he didn't have the power at LHW that a lot of these guys have. I'm talking 190 flat for him not under 190.
If were discussing small heavyweights only. Dempsey, Marciano, Patterson. If were talking any weight under 190. Foster Jackson ,(Julian) Little Red Lopez Garza a few others...