I always thought it was Bob Fitzsimmons but i'm hearing more about how Stanley Ketchel had to have his sparring partners wearing baseball chest protectors, both fighters proved their power at heavyweight but which one hit harder in your opinion ?
Ketchel didn't prove his power to anything like the degree that Fitz did at HW. At MW, there is an argument to be had over who hit harder, but up at HW, it's Fitz all over. Unquestionably the better of the two punchers.
Fitzsimmons was undoubtedly the more dangerous puncher, but you could make an argument that Ketchel had more one punch power, on the grounds that what Fitzsimmos did was partly down to delivery. I would personaly have little enthusiasm for the prospect of being hit by either of them.
I would say Fitz hit harder...but I think it has been said that Ketchel did the shift quicker, and was overall faster than Fitz also...
I wouldnt have thought it close, tbh. I get the feeling that Ketchell had a better workrate, but would consider the difference in power almost like comparing Hagler or Hearns to Tyson. Fitz had true heavyweight power. Ketchell may (or may not) have knocked down a great heavyweight, but the reality was that that great fighter largely wasnt troubled by Ketchell's power. I am pretty sure Langford, Choynski, Maher and many others hit a level above Ketchell.
'Ruby Roberts' punch power was superior to Ketchel. However we do not know if Ketchell would have developed a more powerful punch as he got older, as of course Ketchels life was ended at age 24 by Walter Dipleys bullet