Monday, June 15, 2009

Mid-Season Managerial Changes, 1982-2008

Disclaimer: This is not so much a study as it is a collection of data. There is no claim that the data is statistically significant; although I will use it in the course of discussion, I am not making any formal claims. You will also note that I have included a number of graphs; they don't do much for me (I'd rather just have the data table), but some readers may find them helpful in this case. With any of the images, you can click on them to enlarge as they may be tough to read otherwise.

I started with 1982 because it seemed like a good cutoff point--I didn't want to go too far back, and strike years cause a bit of a problem. I'm certainly not claiming that there is any fundamental difference with regard to managerial dismissals between, say, 1978 and 1982.

I counted all permanent managerial changes that occurred during the season with four exceptions, identified by either the Sports Encyclopedia: Baseball or my memory as not baseball related. The three exceptions are:

1. Dick Howser, KC 1986--medical issue
2. Pete Rose, CIN 1989--banned from baseball
3. Tommy Lasorda, LA 1996--medical issue
4. Larry Dierker, HOU 1999--medical issue

Only the first change is counted for any team-season. If there is an initial interim replacement, and later a permanent replacement, I have lumped them together as most of the interim stints are just a couple of games. I have tried to use the word "change" primarily, but sometimes I have lapsed into "fired", even though some certainly were resignations (and unless my memory from two years ago has been completely fried, Mike Hargrove's departure from Seattle really was a resignation). I'm not using "fired" as a technical term, here, okay?

I have a link to the spreadsheet I used at the end of the post, if you are interested. I am going to do this in a Q-and-A format:

At what point in the season did managerial changes occur?

The earliest (in terms of games) changes came after six games: Cal Ripken (BAL, 1988) and Phil Garner (DET, 2002). Each team started 0-6.

The latest change came after 160 games, when Larry Bowa (PHI, 2004) was let go and Gary Varsho managed the final two games.

The average change came after 80 games, which seems logical. The median was 75.5 games. No team made a change at the exact halfway point of 81 games; in 1990 both Jack McKeon (SD) and Whitey Herzog (STL) were replaced after 80 games, while Bob Boone lasted 82 games for KC in 1997 and Jerry Narron the same for Cincinnati a decade later.

Here is a table showing the number of games elapsed when a change was made. "0" means that the change occurred after 1-9 games; "10" after 10-19; and so on:

And a graph of the same:

The pattern seems to be a lull after the All-Star break; if you make it to the halfway point, are relatively safe for a month, month and a half. Then things pick up again towards the tail end of the season.

Which franchises made the most changes?

During the period in question, every major league franchise has made at least one mid-season change. I expected that the team with the most would be the Yankees, but I was wrong--they are in an eight-way tie for fourth with five changes. The Reds have changed managers seven times mid-stream since 1982 (eight if you count Rose's banishment):

1982: Russ Nixon replaced John McNamara
1984: Pete Rose replaced Vern Rapp
1993: Davey Johnson replaced Tony Perez
1997: Jack McKeon replaced Ray Knight
2003: Ray Knight and Dave Miley replaced Bob Boone
2005: Jerry Narron replaced Dave Miley
2007: Pete Mackanin replaced Jerry Narron

While there are five teams that made just one mid-season change, but three are fourth-wave expansion teams (and two of them have pulled the plug on their manager in 2009). The two longstanding franchises that made just one change are Pittsburgh (Pete Mackanin for Llloyd McClendon, 2005) and Los Angeles (N) (Glenn Hoffman for Bill Russell, 1998).

Has the frequency of mid-season firings changed over time?

Indeed it has, and the change to the division/playoff format of 1994 *appears* to be a reasonable explanation for the altered behavior. Here are the changes by year; N is the number of major league teams:

The maximum of 31% (8 of 26) was reached in both 1988 and 1991. The only seasons without any changes were 2000 and 2006. Here is the percentage in graph form:

I also figured a moving three-year average and produced a graph (the years on the x-axis are the first years of the three-year period):

1992-1994 saw a nosedive in the frequency of firings, one from which there has been a bit of a recovery, but never to a frequency any higher than the 1991-1993 period. 1994 certainly poses a problem due to the strike (and 1995 to a lesser extent with a 144 game schedule), but even if you ignore the three-year periods starting between 1992 and 1994 (i.e. those that include 1994), the rate of changes has dropped.

It certainly seems logical to me that the existence of four additional playoff spots led to a reduction in firings. More teams remain in the hunt despite slow starts, and a slow start is easier to overcome.

Summing it up, in the period 1982-1993, 19% of teams fired their manager mid-season. From 1996-2008, that rate has fallen to 10%. A difference of about 9% in a league of thirty teams is three (2.7) fewer changes per season.

Did teams improve their record after the change?

Yes, they did. The composite record prior to changes was 3562-4580 (.437); after changes it was 3881-4390 (.469). The total season record for the teams was 7443-8970 (.453).

76 of the 102 teams had a better record after the change than before (75%).

Of course you have to be very careful with this data. Cito Gaston was fired with a 72-85 record in 1997 and Mel Queen took over and went 4-1. Thus the 1997 Blue Jays count as a team that improved their record, but obviously one would not want to draw any conclusions from five games. Teams like that also can cause the aggregate records to be distorted.

Nonetheless, I am comfortable with the conclusion that teams generally had better records post-change. The improvement from aggregate wins and losses was .032. The average improvement (weighting all teams equally, even teams like the Gaston/Queen Jays) was .055. The median of the same was .045.

A better approach might be to take a weighted average, with the weight determined by the minimum of games before/after the change. Gaston managed 157 games and Queen managed 5, so the 1997 Jays will be weighted at 5. A team in which the change was made at the exact halfway point would get the maximum possible weight, 81.

Doing it this way, the average improvement is .046. Attempting something else in lieu of more advanced mathematical techniques, one could try weighting by the harmonic mean of games before and games after (2*before*after/(before + after), which you may recognize as Bill James' Power/Speed Number. It's also 2/(1/before + 1/after)). Done in this manner, the weighted average improvement is .049.

But don't teams that fire their managers generally feel as if they are underperforming? Could some (most? all?) of the difference in performance after the change be a result of regression to the mean?

Now that is a good question. And yes, I believe that is what is really going on here, although what follows in no way proves it.

What I would really like to do, if I had a lot more patience for this kind of thing than I actually possess and a better database, is this:

1) figure an expected record for each team in MLB during this period
2) for each team that made a managerial change, find a team (or teams) with similar records and expected records at the point at which the change is made
3) compare the performance of the teams that made a change with those that stayed the course

I *suspect* that if one did such a study, they would find that the performance of the two groups of teams was very similar, and that there was little proof that the managerial change was the impetus for improvement.

I do have a poor man's study here for you, though. In the Bill James Guide to Managers, James figured an expected record for each team based 50% on the previous year's record, 25% on .500, and 12.5% on each the second and third most-recent records. For example, the Angels played .438 ball in 1993, .409 in 1994, and .538 in 1995. So their expected record for 1996 was:

.5(.538) + .25(.500) + .125(.438 + .409) = .500

I figured expected records in this manner for each team that made a managerial change. Obviously, this is a crude approach and thus the study built on it is crude.

The teams that made managerial changes had a combined expected record of .492. Before the change they were had an aggregate W% of .437; after, .469; and for the season as a whole, .453. At the time of the change, 91 of the 102 teams had a lower than expected record (89%).

So one might well expect that many of these teams would improve on their own, whether a managerial change was made or not. It is of course impossible to say to what extent that is true . One must grant the possibility, however far-fetched it may be, that these managers were all an albatross around the neck of the club, dragging it down and preventing it from reaching its true potential. I don't buy it, certainly not in the majority of cases. Managers are relatively fungible, and so they are offered up as penance for a poor season, demonstrating to the fans or the players or the media that the brass is being proactive.

The teams went from playing at 89% of expectation before the change to 95% after. Even after the change, the teams did not play up to expectations, but the method of setting expectations is nowhere near accurate enough to get carried away with this tidbit. Ideally, the actual rosters would be used to set expectations, and you would account for injuries and the like.

Here is a spreadsheet listing all of the changes, along with the expected records.


  1. I tried to tackle this question some while ago:

  2. A couple of miscellaneous factoids I had intended to include, but forgot about:

    * The Yankees made mid-season changes in three consecutive seasons (1988-90); the Mariners in three straight and four out of five (1983-86, 88).

    * In 1986, four of the seven AL West teams made changes, plus Dick Howser had to resign in Kansas City as mentioned in the main post. Only Gene Mauch (CAL) and Bobby Valentine (TEX) made it through the season.

  3. There have been three recent attempts to post a comment for this blog entry. It might be a spammer, but if it is, he's the most persistent I've seen here. Whoever it is, the posts I get to see are completely unintelligible and filled with symbols that my computer does not display properly. So if it's a real person with a legit comment, I'd love to see it, but you're going to have to put in some format I can read.


I reserve the right to reject any comment for any reason.