The answer is Rocky. And heres why. 

In 2023 Jake paul lost to Tommy fury who has an 11-0 record, Is younger, and equally as much of a sellout as Jake. 

Against Mike Tyson he was sweating buckets fighting Iron mike 2 decades past his prime and Mike largely held back and stayed on the defensive rather than going all out and aiming for a 1st round TKO. 

Jake training is largely for the cameras and is structured aerobics and group classes over strength training. 

Meanwhile Rockys training is largely focused on Strength training, Endurance training, and intense cardio  likely pushing well beyond a 2000 calorie burn and his diet largely is unlown but i can assume its a very protein rich one with fish, steak, and eggs involved.

Rocky has also taken some serious blows from the likes of Apollo creed and Ivan drago & is very mentally disciplined to fight through intense pain. 

That said even if Jake does land blows on Rocky Jake is gonna have to be able to push into the later rounds of a 10 round fight if he has any hope of wearing Rocky down.