With this latest win Dubois now has the 2nd highest KO percentage(95.25) of any HW contender ever behind Deontay Wilder(97.69). Before the Hrgovic fight he was tied with Bruno for this distinction. Through his first 21 wins he has had only had 1 decision. This could change quickly I vaguely remember AJ having 100% for awhile. But right now Dubois is number 2.
If we're talking any HW Champion or Challenger ever, I believe Wilder had a 100% KO percentage heading into the Stiverne fight, which was for a belt.
That KO math only includes victories. It should include all opponents. Dubois has stopped 20 of his 23 foes so his KO percentage is 86.95%. This is just another thing that BoxRec does wrong. A a point of comparison, Rocky Marciano is at 87.75%, Wilder is at 87.50% and V. Klitschko is at 87.23%. As a side note, until his last four fights, George Foreman had knocked out 68 of 74 opponents for a spectacular 91.89%. Apparently, he finally lost his power at the age of 46 as he didn't stop any of his last four opponents. Pretty amazing.
So far so good, but KO% tends to drop off when you step up. To be fair he stopped a legit guy in Hergovic.
Foster had been knocked out by Quarry before he fought Ali. Unless you’re referring to KO to win percentage.