Re: Who was more past their prime: Dempsey in 1926 or Louis in 1946??
I'd say Louis. His steady slippage -- although he was still the best in the world in 1946 -- can be seen fight by fight through the latter years of his reign.
I don't think Dempsey was so much past his prime as he was rusty, and then he ran into a guy who would have probably given him fits and thoroughly outboxed him at any point in his career.