I think Burns was 1-2 weight classes bigger, had the better skills on offense and defense ( Ketchel had no defense ) the edge in the chin department, and more reach and better footwork. Both guys had plenty of stamina and heart. While I think Ketchel will have his share of moments, I like Burns via late round stoppage here.
The Ketchel via decision votes to me are the least likely. If a KO did not occur Ketchel's record was just 3-2-4. In other words he did not win the majority of decisions. On film he looks very crude with poor defense, and little offensive imagination. While I have not doubt he was an all time hitter at 160 pounds, that doesn’t mean he could starch fighters at 170-180. In fact did he KO anyone over 170 pounds? Example Bob Foster had all time power at 175 pounds, but his power did not go up in class to heavyweight, even vs. 190 pound ranked guys.