I think the idea that Dempsey's 1918 run was not impressive is a ridiculous notion. People, YES, please go out and do the research in the newspapers of the time.
More than one writer was saying that Dempsey was virtually the champion of the world (there was serious doubt over whether Willard would fight again), and it was just a case of Willard relinquishing the title. Dempsey's KO of Brennan, the manner is which he beat him, made people sit up and take notice that Dempsey had developed beyond a run-of-the-mill contender, but the 23 second blow-out of Fulton put Dempsey into a league of his own. Loads of other KOs over journeymen and experienced veterans confirmed his ability, speed and brute force. Even his nemesis Willie Meehan, who nicked a 4-round decision, was dumped on the canvas and had to run for his life.
It's like arguing that 1986 wasn't a good year from Tyson.