I think prime Chavez (and did probably peak at 135), breaks down Buchanan late, probably winning in the championship rounds. But Ken's speed and brain would have caused Chavez problems in the first half of the fight. I would have posted this thread in the classic forum, it would have got more responses.
Buchanan was a class operator, and wouldn't be an easy night's work for any lightweight in history. While he was one of the best fighters in history at applying educated pressure, Chavez wasn't a ferral force of nature like a young Duran and wouldn't overwhelm Ken in the same way. It would probably be more of a chess match early on with Buchanan more than holding his own. Agree with TBooze though that Chavez was at his best at 135, and he was a complete fighter during his brief stay at that weight. I think to get the measure of Chavez you really needed to hurt him and get him on the back foot. Taylor was able to do it with flurries and win the exchanges, and Whitaker hurt him to the body on several occasions. I don't see Buchanan being able to do that, and the Chavez who broke down Rosario would eventually start outlanding, and pushing Buchanan back to the ropes. Buchanan had a very good chin and it's unlikely to be a stoppage, but Chavez should win a hard-fought decision.
