Former major leaguer Steve Sax recently said that he thinks a good manager is worth an extra eight to 10 victories a year for his team. When it comes to Gibson, a former teammate of his with the Dodgers, Sax says that number could be higher - even though this is only Gibson's first full year as a manager. "You take somebody like Kirk Gibson and he might be a 15-game difference," Sax said. "And I say that because this guy is pretty dynamic. You're talking about one hell of a tenacious guy who knows how to win."
-- Arizona Republic
I'd be curious to hear details of the logic here. Why is is 9-10? Why not 4-6, or 12-15? Is there, in fact, any actual logic here, or is this simply a gut feeling?
In the modern (post-1950) era, the manager with the best W-L record is Al Lopez, who pips Earl Weaver by .001. Between 1951 and 1969, he went 1410-1004, a win % of .583. That works out to 94 wins over a 162-game season. The best among those currently active is Joe Girardi, who is at .563, which is 91 wins, with the #2 Bobby Cox (.556, 90 wins), which would seem to support Sax's view. Here the list of the top and bottom five, among active managers (min 320 games).
Interesting to note Joe Torre and Tony LaRussa, names I'd reckon would generally be reckoned among the "best" managers, aren't mentioned, falling outside in the top five (at #7 and #8 respectively). However, the obvious question is, how many of those victories can we really ascribe to the manager? It's certainly hard to deny that Girardi's sterling record is at least partly due to the fact that he has managed the New York Yankees for three of the four seasons. Really, if you can't be above .500 with a $200 million payroll, averaging $55 million more than the #2 team...well... I note Girardi's record when he managed the Marlins was a pretty mediocre 78-84.
There's another uncomfortable fact Gibson's boosters need to explain. A.J. Hinch's record as a manager was 89-123, a W% of .420. Gibson's record is currently 34-49 - a W% ten points less. Even if you take the same time-frame, and cover only Hinch's first 83 games, the gap actually expands, as his W% there was .458. This is not to say that Hinch is "better" than Gibson - just that, at the very least, there doesn't seem much evidence to support Sax's claim, as far as any immediate improvement goes. And I'm not sure how much we can ever get: the radical roster overhaul makes future comparison, without other factors muddying the waters, almost impossible.
But I think it's notable that baseball managers are paid a lot less than their counterparts elsewhere. A 2007 study showed they were paid an average of $1.3 million, one-third of the average for an NBA coach. That probably gives you as good an idea of a typical managers' "worth" as anything - apparently about the same as a first-year arbitration player.
For more on the topic, see this interview with Chris Jaffe we did last year, regarding a book he wrote on the topic, Evaluating Baseball's Managers.