It is debatable, unfortunately any attempts to quantify become loaded with assumptions. I think Passan had an article recently where a manager was quoted as saying they basically did nothing, but this is an opinion I have that doesn’t have data. Just a hunch with a lot of plausible speculation.
I think it’s more nuanced than “nothing”. I also think it’s so minute and unquantifiable that it’s uselsss to argue about it.
I don’t think it’s coincidence that Showalter always overperforms for a couple of years... and then unpeforms for a couple of years before getting the axe. Or that Gardenhire had a solid run of overperformance before collapsing. Or that Molitor has been up and down, as weird as that sounds to say.
Or that Maddon is almost *always* good.
How can we quantify that as outsiders? Um... yeah. We can’t.
So we should evaluate the themes, ideas, and styles of managers... and STFU about the rest because we’re talking out of our asses.