Dusty Baker and Pitch Countsby David Gassko
May 26, 2006
Mark Prior and Kerry Wood have combined for two starts this season. They combined for 31 starts last year, 43 the year before that, and 62 the year before that. The pattern is pretty obvious, but here's the question: Is it Dusty Baker's fault?
Baker has long been known to put little stock in pitch counts. He's had a pitcher finish in the top-eleven in pitches thrown each of the past six years, and he has left the starter out there for 122 or more pitches 88 times this millennium, more than any other manager.
In Chicago especially, Baker has come under a lot of criticism because he inherited a young staff full of special arms with the Cubs. And he's proceeded to ruin it. Kerry Wood? Got sent to the bullpen last year his arm was in such bad shape. Mark Prior? Hasn't had a full season since 2003. Only Carlos Zambrano is still standing, and even he has shown signs of struggle due to Baker's slow hook. After a start last May in which he threw 136 pitches, Zambrano said that his arm felt like "concrete."
Baker belongs to the old school of managers. About 10% of his pitchers' starts go over 120 pitches, and he's apt to leave his starter in too long than go to the bullpen too soon. He's among those that believe if pitchers could handle it in back in his day, they can handle it now—PAP scores be damned.
But entrusted with such a young and talented pitching staff, Baker has been placed under a microscope over the past three years. The Cubs have gone from first to third to fourth in their division, and this year looks even bleaker. And Prior and Wood, who once looked like a Hall of Fame one-two punch ala Sandy Koufax and Don Drysdale or Randy Johnson and Curt Schilling, have spent more time in the trainer's room than on the mound.
Now, the call for Baker's head is growing louder and louder, in no small part due to his mishandling of the pitching staff. A website called FireDustyBaker.com has been pulling in traffic for a year now, and making a statement. Cubs fans are sick of Baker's managing style. They're sick of seeing high pitch counts and fatigued starters. Many want Baker gone. But for what? How much further does Baker drive his pitchers than the average manager?
First, let's look at pitchers who have either left or come to Baker's teams starting in 2000. Did they pitch more with Baker than with their other teams? Over the past six years, there have been 17 such starters, including three different instances of Shawn Estes, which really makes me think that Dusty has an unhealthy obsession with the guy.
In fact, these 17 pitchers did indeed throw more innings per start with Baker at the helm, though the magnitude of the difference was not as great as might have been expected. In total, Dusty Baker added 3.09 pitches to each start, or about 100 pitches a season. Basically, pitching for Dusty was the equivalent of making an extra start—probably not a killer.
But while comparing a pitcher's years with Dusty as the manager to the years surrounding helps eliminate a lot of problems, since we're comparing pitchers to themselves, it is not a method without problems. First of all, our sample—only 17 pitchers—is kind of small. Secondly, we don't know what impacted their pitch counts without Dusty. Maybe they were just worse pitchers without the guru of the complete game?
So let's try another method, just for fun. Let's take every pitcher season beginning in 2000, 394 in total, with six seasons worth of data, and try to predict pitch counts while controlling for everything in the universe that needs to be controlled for. In this case, "everything" means hits, walks, strikeouts, league, and year. Essentially what we're asking is this: "Given that a pitcher allowed this many hits and this many walks, struck out this many batters, played in this season, and in this league, how many pitches per start would we expect him to throw?"
Why all the controls? We want to avoid biases. For example, while Baker is often accused of making Prior or Wood or Zambrano throw too many pitches, the fact is, they should be throwing more innings than the average pitcher, because they're better than the average pitcher. Perhaps it's not that Baker overuses his pitchers, but that he simply has been blessed with a good starting staff.
That's actually probably part of the answer. Nevertheless, even after we control for all these variables, Baker's pitchers still throw 3.68 more pitches per start than expected. That's maybe an extra start-and-a-fifth a year. It's about 5-10 extra innings.
So it seems that to claim that Baker ruins pitchers' careers is hyperbolic at the least. Even if we account for the fact that younger pitchers should probably be throwing less innings, Baker still isn't quite the monster people make him out to be. Nevertheless, if he is worth 5-6 extra pitches per outing for a young pitcher, that may indeed be significant. There's certainly no reason not to be on the cautious side, and Baker's lack of caution with high-pitch outings is certainly disconcerting.
But Dusty Baker is not a professional arm shredder; he only leaves his starters out there for about three-and-a-half more pitches than expected. Prior and Wood have had injury troubles, but so do many young pitchers. Perhaps it isn't Baker, but just bad luck. Perhaps the Cubs should have never pissed off that Billy Goat.
References and Resources
You may be wondering how I arrived at the 3.67 number. I used an ordinary least-squares regression with Pitches/Start as my dependent variable, and Year, Hits/BFP, BB/BFP, K/BFP, NL, and 'Baker' as my independent variables. The Years were there essentially as constants. Hits had a negative relationship with Pitches/Start, as you might expect, so the more hits a pitcher allows per plate appearance, the more likely he is to be pulled early. Walks and Strikeouts both had a positive relationship, though the coefficient for walks was somewhat unexpected. The most likely explanation is a combination of the following three things: (1) Walks have a positive correlation with Ks, and high-K pitchers will generally be the ones who stay in for longest, (2) It takes a lot of pitches to walk a batter, and (3) A walk are not as costly as a hit, so a high-BB pitcher can still be good. The results of my regression are listed below. All estimates were significant at the 1% level.
Variable Coefficient T-Value Sig 2005 99.396 17.716 .000 2004 100.245 17.737 .000 2003 100.021 17.982 .000 2002 100.002 18.013 .000 2001 99.654 17.625 .000 2000 102.823 17.961 .000 Hits/BFP -44.966 -2.672 .008 BB/BFP 40.235 3.189 .002 K/BFP 44.491 5.438 .000 Baker 3.677 3.009 .002 NL -2.243 -4.320 .000
StatScape: Making Pitch Count Work
Baseball Prospectus Pitcher Abuse Point Reports
David Gassko is a former consultant to a major league team. He welcomes comments via e-mail.