At the Final Four earlier this year, I was chatting with a few people who work in Michigan State’s basketball program when the conversation turned to Michigan. The schools have had an unusual rivalry in recent years: Both teams have been national contenders, and their games have been intense, but there is an extremely high level of mutual respect that, unfortunately, the football programs don’t seem to have at the moment. Still: if you work in one program, you really don’t get a close look inside the other. One of the MSU staffers asked how John Beilein’s Michigan program compared to Tom Izzo’s at Michigan State.

I said the difference, at least to me, is that Izzo’s players see him more as a father figure. He gives them tough love, and they don’t always understand it, but in the end they feel extremely close to him. Beilein’s players see him more like a brilliant professor. Most don’t get to know him quite as well, but they admire and respect him, and they apply his lessons long after they leave.

On Monday, the professor left academics.

“It’s sad,” Izzo told me, and he meant sad for his sport, not for Michigan or Michigan State or Beilein. “I do think, honestly, he was a very good coach that did it the right way and brought this into a true college rivalry. I hope he’s leaving for the reasons that are best for him. I hope it’s not for other things.”

When Beilein addresses the media for the first time as the Cleveland Cavaliers’ coach, he will surely say it’s a wonderful opportunity to build a team at the highest level, working with people he likes, in relative proximity to most of his family. I’m sure that’s all true. I doubt this is that simple.

The other things in college basketball are numerous. Some are obvious, but some of the less obvious ones probably played a bigger role. Of course the rampant cheating in the sport had to bother Beilein, who is widely considered the cleanest big-name coach in the game. But also: he is, at heart, a teacher. And college basketball is not really a teacher’s sport anymore, not like it was.

Rosters turn over every year. Guys who are fringe NBA prospects and good students leave school early, or at least test it. The transfer market gets more active every year, and rules keep getting more lenient so they can go wherever they want and, in some cases, play right away.

You can argue that this is all progress, and maybe some of it is. But if a sport loses John Beilein, that sport has a problem.

College basketball appears to be run by some combination of a drunk driver and a Twitter poll. There are a lot of individual developments that seem logical on their own but have collectively created a kind of madness.

An example: Coaches cannot work out their players during a window around final exams, because players are supposed to be studying. Sounds good, right? Well, now some of those players can and do declare for the NBA, and they are allowed to work with agents, and those agents can bring people in to work out the players during that same window … in the college coach’s gym. Does that make sense?

Michigan just lost sophomore Jordan Poole to the NBA, and freshman Ignas Brazdeikis is almost certainly gone, too. Both have a chance to be solid pros. Neither is ready. They have every right to leave before they are ready, of course, and to get paid while they spend one to three years developing into legitimate NBA players. But if they’re leaving one of the game’s best teachers to develop their games, you can understand why the teacher would leave, too.

Outside of his family, Beilein has gotten his greatest joy from helping young men improve at basketball from the ages of 18 to 22. Some of that joy must get diminished when players are leaving as often as they do. Those departures create more headaches: a full-year recruiting cycle, constant juggling of the roster, a coach who never really knows who he will get to coach.

Beilein is so skilled that he kept winning anyway. But it’s not what he envisioned when he got into college coaching, or even when he took the Michigan job in 2007.

He leaves Michigan as the school’s greatest coach, and more than that, as its ideal one. Every year, Michigan fans felt like their team had a chance because their coach was so good. Beilein would figure it out, somehow. And every night, Michigan administrators went to bed knowing their basketball program would not embarrass them. You looked at the team bios every year and you saw real majors. You looked at the police blotter and you almost never saw his players’ names.

Finding another John Beilein will be virtually impossible. There was only one like that. But Michigan athletic director Warde Manuel would be wise to get as close as he can. Michigan is a great job, but there are more ways to mess up this hire than to get it right. The best résumé often does not make for the best hire. There are coaches who would chafe at the school’s academic standards or the attention the football program gets, and others who regularly break rules that Beilein would never consider bending. The best assistant Beilein ever had, Butler’s LaVall Jordan, deserves a strong look.

The Michigan job will be another coach’s pearl now, and the transfers and annual NBA waiting game and dirty recruiting game will be another coach’s problem. Beilein moves on to Cleveland—to having his summers off, his players under contract and his focus completely on teaching basketball.

With the right roster and patient management, Beilein can be a great NBA coach. But I think back to one recent Final Four that Michigan wasn’t in. I was chatting with Beilein about one of his players who had left school early with no guarantee he would play in the NBA. Beilein supported the player but I don't think he understood the decision. He looked around the dome, shook his head, and said, “This is pretty good.”

Very few people ever loved college basketball the way John Beilein loved it. How sad for the sport that, in the end, he decided he would be happier doing something else.