For a long time there has been debate about who was the strongest between Whitebeard (the Strongest Man in the World) and Kaido (the Strongest Creature in the World).
Looking at chapter 970, I noticed how weak Kaido was presented.
I know that he might not have been at his prime and all, but take note during this time, he was already past the time of the ROCKS crew, so to those saying he was weak because he was not yet at his prime, take note that he would’ve already been strong enough to be formerly a part of Rocks D. Xebec’s crew.
So Oden roughing up Kaido and even scarring him despite suffering strain already from fighting Kaido’s army tells me that if Kaido’s crewmember didn’t play dirty and hold Momonusuke hostage, I personally believe Oden could have ended Kaido right then and there.
There are theories going around that Oden might still be alive (time travel from Toki), if so, he could finish his fight with Kaido soon and end the overhyped beast.
So, if Oden was struck down by Roger in one hit, and Roger is equal to Whitebeard (during their prime), it would then follow that Whitebeard at his prime way trumps Kaido.
I think Kaido was just overhyped with his epithet and introduction. If it was mentioned later on after his introduction that he had been beaten and captured several times, I believe we would also lower his strength from our perspective. It’s just Oda’s knowledge of how first impressions affect people that he was able to hype Kaido. What a brilliant author! He’s a genius in presenting the elements of his story.
*by KiyotakaTatsuya