Tank Davis and Anthony Joshua The greatest examples of intelligence. With a combined IQ of 82, there's no limit to their special potential
Currently Tyson Fury. He is very smart to pick the right opponent at right time. He avoids risky fights. Plays mind games. Can make up lots of excuses. Knows the politics of the game well. Of all time, Ali, of course.
Outside the ring, Ali was cost some of the best years of his prime due to his devotion to a murdering cult that believed that aliens were going to arrive in their spaceship and take the members away to another planet, I believe his true home planet. Inside the ring, his master strategy once his athleticism deserted him was to absorb punishment which on later life reduced him to a shambling shell of the physical brilliance he once exhibited. ATG fighter but no genius inside or outside the ring.
Sadly, this is the correct answer. Fights joke, no-risk fights and gets paid many times more world champion fighters that beat the living hell out of each other.
Fury beats Paul to it. Seferi, Schwarz, Pianeta, Wallin, Whyte, Chisora... And he demands £500M for Usyk fight.