On Saturday, I posted a follow-up to a recent Fangraphs’ analysis of relief pitchers’ aggregate performance over the last 30 years. Although my findings supported the statistical conclusion of the Fangraphs’ piece (i.e., reliever performance has not changed meaningfully over the period considered), there was a divergence with regard to the implications. However, because both analyses only looked at the question from the perspective of relief pitchers, each conclusion may have been incomplete .
Prompted by a comment from MikeD, the following analysis examines the question of bullpen usage from the perspective of the starting pitcher. After all, relievers are only needed to the extent that starters are unable to complete games. Therefore, the usage pattern for the rotation must have an impact on how the bullpen is employed.
Percentage of Batter’s Faced by Relievers and Starters, Since 1982
Source: fangraphs.com
Based on innings pitched and batters faced, it appears as if starters are currently going as deep into games as they were in 1982. However, looking at the aggregate total disguises what may be more meaningful trends. For example, since 1919, there has been a gradual decline in the rate of complete games, and even when compared to 1982, the drop has been significant. But, how does this impact bullpen usage?
Rate of Complete Games, Since 1919
Source: Baseball-reference.com
Going to the extreme, in 1919, starters finished over 60% of their games, so well over half the time, the manager didn’t have to worry much about the bullpen. Fast forwarding to 1982 (one of the parameters of the previously cited analysis), the complete game rate had fallen to 17.4%. Despite a much lower percentage, a manager in that era could still bank on full rest for his relievers coming once every five games. In today’s environment, however, a night off for the bullpen is a very rare occurrence. As a result, modern managers are faced with the challenge of spreading their bullpen assets over a greater number of games.
If complete games have decreased significantly, what explains the relatively stagnant workloads indicated by the Batters Faced chart presented above? Could it be that the demise of complete games is merely anecdotal, especially if they are being curtailed simply out of deference to the save rule?
Rate of Innings Per Start, Since 1919
Source: Baseball-reference.com
Looked at more broadly, the rate of pitchers going beyond six innings has declined from over 75% in 1919 to 54% in 1982 and then 43% in 2011. Meanwhile, the number of starts lasting three innings or fewer has also declined, falling from just over 10% in 1919 and 1982 to under 5% in 2011. Because of this convergence, there were more starts that lasted between five-plus and seven innings in 2011 than at any other point since 1919.
Rate of Starts Lasting Between 5 1/3 and 7 Innings, Since 1919
Note: Excludes appearances in which the pitcher appeared in the sixth or seventh inning, but did not record an out.
Source: Baseball-reference.com
Considering the patterns presented in the charts above, it seems as if the evolution toward shorter (but more frequent) appearances has taken place out of necessity. Because very few starters progress into the later innings, managers now must use their bullpens extensively in almost every game. As a result, a “lose the battle to win the war” mentality has taken hold. Whereas 30 years ago, a manager could use a top reliever for several innings because he could count on one of his starters throwing a complete game in the near future, today’s skippers aren’t afforded that luxury. What’s more, it seems as if the need to spread out reliever appearances has resulted in managers being less likely to turn the game over to the bullpen in the early stages. Without room on the roster for a true long guy who could be exhausted for an extended period of time, “saving the bullpen” has become another common mantra for the modern manager.
One final point worth noting is just because relievers aren’t throwing more innings or facing more batters doesn’t mean they aren’t working harder. Along with more appearances come more warm-up throws (what managers today call “getting hot”), many of which occur in games the reliever never enters. Although this doesn’t show up on the stat sheet, it is something that managers take into account when making decisions about their relievers.
Whether its “lose the battle” or “save the bullpen”, the modern approach to managing a bullpen seems designed to mitigate the risks inherent in having a starting rotation that is unable to provide length on a regular basis. Based on the evidence, it doesn’t seem as if managers could simply reverse course and readopt the bullpen management philosophies of the past. Instead, innovations in bullpen management should be focused upon optimizing leverage, or other modifications to current strategy, because today’s starting pitchers simply wont allow relievers to be used as they were in bygone eras.
Thanks. I didn’t mean to set you off on a new analysis, but glad it did, since it’s a topic that’s been on my mind, which drew me into your article as well as Cameron’s.
What caused me to think about it (at least more than usual) was a recent story noting that supposedly Mariano Rivera will make a decision by spring training on if he intends to pitch beyond 2012. It got me to thinking, what will the Yankees do? Sure, they could go out and get another closer, or elevate an existing reliever to closer, but that pitcher will be under heavy scrutiny, especially a high-paid outsider. So perhaps in Rivera’s retirement, the Yankees can reinvent the closer role by not having a single closer, but multiple relievers, say Robertson, Chamberlain and Hughes, who would share late-inning duties, being called on not to pitch an inning at a clip, but multiple innings.
That caused me to think back another step. Okay, if the Yankees have three late-inning guys, who are the middle men, and how are they impacted? That leads back to the my original question or observation, which ultimately is that all this is driven by the starters. How deep they go into the games impacts tremendously how the relievers are used. Managers today have a much more complex job in managing arms and workload. It’s not just bullpen management, but the management of the entire pitching staff. Joe Girardi gets picked on for his “binder,” but one of the things he tracks is bullpen usage, including not just when and how many pitches his relievers throw in a game, but how often they warm up, and how many pitches are thrown in the pen. Having watched this game since the 1970s, I can assure you that’s not something Billy Martin and Art Fowler were concerned about!
So I think you’re spot on. Bullpens have evolved to how they’re used today out of necessity. It won’t be all that easy to go back thirty years, and I don’t know if they should or even could. The money being paid to starting pitchers today is so high that they are treated as an investment. They won’t be asked to pitch more. They’re more protected, and that’s probably a good thing. What happened to Catfish Hunter in 1975 would never happen today.
That all said, how pens are used can be done better, but the save rule has complicated it. Rivera, and all people payed to close games, are pretty much restricted to the 9th inning, yet the most critical time in a game may happen in the 7th inning. Getting back to the time when use of the most effective arm is dictated not by the inning but by the high-leverage situation, is the real change that’s needed.
I have no idea how we’ll get there.