Baseball has given out official Manager of the Year awards only since 1983. That first year, the winners were Tommy Lasorda and Tony La Russa. By that point, eons of evolution had shifted the definitions of what a baseball manager even did.
If they had given out the award 60 or 70 years before, it would have been a lot easier to choose. Managers in the early part of the 20th century were mini-dictators. Among their expected functions was overseeing the procurement of talent, its development and the way it was deployed on the field. Baseball writer, historian and statistician Bill James likened the role of the field general back then to that of a modern-day college football coach. World Series billboards for, say, 1921, instead of touting "Giants vs. Yankees" might have had a headline billing of "McGraw vs. Huggins." You want to pick a manager of the year? Look at the standings.
Things have become ever so much more complex since then. Despite the avalanche of data at our disposal, we've gotten no further in measuring the single-season performance of a manager than where we were in 1975. It's a gap we are never going to bridge, because to truly judge the work of a 2019 manager, we would need to spend every day with him, through his conversations with his front-office collaborators and his consultations with his coaches and -- perhaps by spying -- also know how he is discussed among the players in the clubhouse. In an age when we measure everything, we cannot measure the manager.
Or at least we can't through the prism of a single season. One assumption we can make in this hypercompetitive industry is that if a manager is not functioning in a way that benefits his organization, he is not going to be perched on that team's top dugout step for any longer than necessary. Thus, with a big enough sample, we gradually learn who the best are at this esoteric craft. The proof: They keep getting invited back.
Who are the best active managers? Let's consider a ranking based on a version of Fibonacci Win Points, another James invention that he has used a few times over the years to examine starting pitchers. Inspired by that, I began to keep a spreadsheet that used the same formula to rank the career performance of managers.