Mismatch, Ruiz would win on points 12 round shut out. Kownacki has the worst defence I've ever seen a top 20 HW have.
As bad as shape as Kownacki is, he's never shown up as heavy as Ruiz Jr has for this fight. Kownacki wins the battle of the scales. I think it would be an entertaining fight though, but I think Kownacki's more consistent work rate would be the difference.
Wilder's defence isn't actually that bad, he uses his height well and utilises a lot of head and upper body movement to evade punches. While he can be hit, he's hard to hit cleanly. Kownacki in comparison plows forward eating punches like Andy Ruiz eats Snickers. But Kownacki seems to have a decent chin, he got his face busted up vs Kiladaze and kept going forward and Martin didn't seem to bother him at all. I don't think Ruiz Jr is big enough puncher or busy enough a puncher to discourage Kownacki from trying to push him back.
The winner between them could be determined tonight ,bc theres no way Kownacki makes a competitive AJ match. Its a slim chance though bc I don't believe Ruiz will look good at all . I would take Ruiz based off he actually fought better guys and Kownacki has slid by Martin . Hes also been around guys WAY more and sparred many top elites like Holyfield so his grasp for boxing seems more well rounded .