Lets say they had a full fight for the championship, at 158, both at their best within that weight. There's actually a much stronger case for Ketchel, than people give him credit for. Ketchel was well in decline when he fought Langford. This was after his poor showing in his last fight with Papke, his fight with Johnson, and he'd been poor in an ND against Klaus, and out of shape Since the fight After the Klaus fight, Ketchel apparently spent time in hospital for a bruised eye and dislocated thumb, and said he'd do no training until he fully recovered Meanwhile Langford was on much better form, the only blemish for a while. being an ND with Flynn, who he'd since stopped. The fight, from what I've seen, seems to have been edged by Langford, however Ketchel was causing Langford problems, and landing some good shots. I don't believe Langford was going easy on Ketchel, if someone has a case I'll be open to hearing it. However the reports say Langford bloodied Ketchel's nose in the 4th, then was aiming for it, and in the 5th loaded a swing so heavilly that he went down when it missed, and lifted Ketchel off the ground with an uppercut in the last round. I have a hard time believing that a fighter wearing the cuffs was throwing bombs like that. So all in all, very diminished, and probably out of shape Ketchel, put up a good fight with Langford. I don't think it's that hard to see a prime Ketchel winning.
Perhaps, as was the practice at the time, he was carrying the Big Named fighter in their first encounter to book a much more lucrative second fight.
I'm inclined to believe Sam did take it easy on Stanley but ,when he realised what he had on his hands had to let some real shots go.My only source for this is Clay Moyle's excellent bio of Sam,and it should be noted that Langford had a significant weight advantage in their scrap .
But then why was Langford throwing such a heavy shot that he himself went down, and risking KOing Ketchel?
Purposely missing,he did the same thing against Jeannette in one fight and Jeannette got in the way of the punch and was ko'd. It''s in Moyle's bio of Langford.
There is some evidence that he carried Ketchell. The Moyle biography gives an in depth treatment of the subject.