As you've surely heard, the greatest coach in the history of professional sports has just retired. I refer, of course, to Sir Alex Ferguson. And I’m not being hyperbolic.

It’s true that coaches have achieved great things with lesser talent. It’s also true that Sir Alex didn’t necessarily “revolutionize” soccer the way that, say, Rinus Michels and Johann Cruyf did with Ajax in Amsterdam. And it’s true that in England's Premier League, Sir Alex has never had to deal with certain constraints -- such as salary caps -- that come with managing teams in the far more tightly regulated sports leagues in the U.S.

Paradoxically, though, having nearly unlimited resources in the world of soccer is not necessarily a blessing. If you think talent evaluation in baseball is tricky, imagine how tough it is in soccer, when you are choosing players from among scores of countries, most with several leagues. Once you have all these players in a single uniform, you have to balance their divergent styles, sensibilities and egos (not to mention languages). And because United was competing for the Premier League title as well as various other cups, Sir Alex had to basically manage two full starting lineup's worth of stars. (And Phil Jackson thought he has his hands full with Shaq and Kobe!)

Apart from being a superb talent evaluator, what made Sir Alex so good? Now we enter the realm of speculation. The rise of statistical analysis has enabled us to see athletes in a fresh light, but when it comes to analyzing coaches, we're still left talking about intangibles.

Under Sir Alex, Manchester United always seemed to play a little bit harder than everyone else. It never gave up, frequently getting a win (or a draw) the final minutes. There was rarely doubt or confusion on the field. Each player knew his task. Over the years, Sir Alex was able to seamlessly slide different players into different roles, balancing talented young players with experienced older ones. He never struggled -- at least not visibly -- to get stars to blend into his system. He was ruthless about personnel, often jettisoning players at their physical and commercial peak if he thought it would help the team.

No matter who came and went, United would win. And the more games they won, the more confidence fans -- and ownership -- had in Sir Alex. In the famously cut-throat world of British soccer, he maintained full job security, managing the Premier League's top team and the world's most famous sports franchise until he decided it was time to step down. He was great because no one questioned his judgment; but no one questioned his judgment because he was great.

This season was arguably Ferguson’s greatest. Manchester City and Chelsea are now free-spenders, too. Sir Alex managed to hold them off for the most part -- until last year, when City won the Premier League and Chelsea the Champions League. United came back hungry for revenge, but with a team that was probably not as strong on paper as either City’s or Chelsea’s. (It was certainly less expensive.) Real Madrid knocked United out of the Champions League, with the help of a very bad call (even Madrid’s manager acknowledged that the better team had lost). But United clinched the Premier League title for Sir Alex’s 13th and final league title.

(Jonathan Mahler is a sports columnist for Bloomberg View.)