Bonecrusher was the first champ with a degree I thought. However, you shouldnt judge someone's intelligence on their degrees. Someone can be Brilliant in their field and rather clueless in other areas. Garner's seven intelligences are interesting: interpersonal, intrapersonal, musical, mathematic, spatial, bodily/kinisthetic, linguistic. He postulates that they are all equally valid. Many of the aforementioned fighters demonstrate High aptitude in several areas. Excuse my ignorance, I didnt know about Dempsey's restaurant. That is very impressive. Its so difficult To run a successful restaurant for That long in NYC. Using Gardners theories Ali probably gets my vote for Interpersonal/intrapersonal. He knew how to read people and had the gift of gab, and knew himself well enough to fight for what he believed in, in and out of the ring.
I'd have to say the Klitschko brothers. They are articulate in a second language, have advanced degrees, and are knowledgeable regarding world issues. Honestly, I haven't heard anyone come close, but haven't heard Tunney speak either. Guys like Lewis, Foreman, etc. are perhaps somewhat bright, and with more education might be considered truly smart. I've actually heard that Sonny Liston was very smart, though his silence often disguised it.
Corbett had worked as a banker before becoming a prizefighter. As a pioneering boxer, he was always looking for new and more efficient methods to perfect his technique. He did this both in training and in actual fights themselves. I heard a recording of him made in 1907 and he speaks very well, sounding more like a renowned professor than an ex-fighter. Jack Johnson was reportedly fluent in Spanish and French. Also, prior to his fight with Jeffries he entertained onlookers by playing a bass violin for over an hour. In the few recordings I have heard of his voice, he speaks like a highly intelligent, well-read individual. Dempsey was mentioned as having been a successful restauranteur on Broadway in New York for many years. While I never had the honor of meeting him, I did go to his wake in Manhattan in 1983. Standing in line with me, waiting for the funeral home to open, some of his old employees were talking about what a great boss he had been. He told them "If the customers want more potatoes, give them more potatoes." and the like. He wanted the customers satisfied, which was key to any successful business. And, of course, he treated them all very well, with class. Tunney was a voracious reader known to hobknob with the likes of George Bernard Shaw. While training for Dempsey, he was seen reading a book. Someone asked what he was reading and was told "Shakespeare." Whether that was true or not, he reportedly did give some lectures on Shakespeare. As a fighter, he intensely scrutinized every opponent he fought, looking for weaknesses to exploit and strategies to employ. When floored for the first and only time in his career, in the return match with Dempsey, he had the presence of mind and good sense to stay down as long as allowed so as to give himself maximum advantage. He was a businessman - his goal as a fighter was to win the title, make a million, marry his heiress fiancee, and retire, which is exactly what he did. In WWII he served in the Navy as a Lt. Commander. Afterwards, he served on the board of directors of several major companies. Like Corbett, his deep voice was more that of an educator than ex-pug. Schmeling spoke German and English. He largely was his own manager. As a fighter, his analysis, preparation, and execution of the first Louis bout was nothing short of brilliant. He had a keen and well-developed knowledge and appreciation of the arts in Germany prior to WWII. After having lost all his material possessions and wealth in the war, he started afresh and built himself into a very successful businessman and entrepreneur - an amazing story in itself. George Foreman, in his second career, was his own manager. He knew how to get what he wanted in negotiations. While the grill marketing may have been handled by others, he was the pitchman and knew how to do it to perfection. I have heard him speak in person and he is a very good speaker and conversationalist. While I am not as knowledgable of the Klitschko brothers, it is my understanding that they both have Ph.D degrees, and that alone indicates high levels of intelligence.
The first name that jumped to me was Foreman. Just always seemed like a smart dude to me, and the financial success he's had in and out of the ring suggests he was certainly no dummy. :smoke
Muhammad Ali,like a lot of people,may not have been intelligent in an ACADEMIC sense,but proved to be among one of the most astute in and out of the ring. That is a form of intelligence.
Holmes has done great job with his money, if he is doing the managing of it himself, he ranks high in that department intelligence wise. marciano knew to get out, and unfairly got labeled as cheap for not letting people in power in boxing make sucker out of him, and he had a tv show, set up own paid appearances, etc. Dempsey did ok in some ways, he was not too money smart, being generous was his fault there, but he made and kept a lot of friends in show business and other circles, had good people skills, and did not screw up as others did.
I personally liked Lennox as a commentator, but he tried to sound too articulate at times, and was often stuck searching for words. That kind of thing is not as easy as it appears though. I thought Lewis did an admirable job. :smoke