Fifteen rounds? Lop-sided decision for Charles. Willard wouldn't be completely shut out, he'd be quite a meal for Charles to get his teeth into, using his strength and weight to maul Charles in the clinches and lift him clean off his feet. He'd probably even whack him hard every now and then, but Charles dealt with far more speedy and dangerous punchers. Interesting fight, if a bit boring. It would consist mostly of Charles conserving his energy and doing enough to win, which would be a lot more than anything effective that Willard would dish out. Charles would be able to land anything he wanted and pull out every trick, but wouldn't dent Willard anywhere near enough to score a knockout. 13-2.
While Willard looked poor vs Dempsey, he pretty much won ever round vs. Frank Moran. I think its Charles fight to lose. If Charles wants to box and play it safe he wins. If Charles fights his normal style, Willard has a good chance to get a knockout win. The shorter the fight, the better Charles chances.