I initially created Baseball Graphs to develop new and better ways of presenting baseball statistics. The 2003 season was my first full-season attempt, and it turned out pretty well. I now spend a lot of my time creating and formatting the baseball stats at The Hardball Times.

Along the way, I've also picked up the writing bug. I spend most of my energy writing for THT, but sometimes I like to write about more geeky stuff, baseball research and things like that. That's what this blog is for.

I'm very interested in graphics and other information display, so I'll probably post links to creative stuff like that. I also plan to write historical articles that complement the historical graphs. And I have inexplicably developed an interest in baseball win-related stats, such as Bill James's Win Shares and something called Win Probability Added. So you can expect a few posts about that stuff too.

If you're interested, I've created a complex spreadsheet full of WPA logic, which you can download at ftp.baseballgraphs.com/wpa. If you'd like to read more about Win Shares, try these links:

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If there is any aspect of WPA, Win Shares or baseball graphics you're interested in, drop me an e-mail and I'll look into it. Syndicate Baseball Graphs:

A Graphical History of Relief Pitching

February 28, 2004

Taking the historic analysis pioneered by Bill James and expanded upon by Mike Carminati, and putting it into graphs.

One of the most intriguing stories in the history of baseball is that of relief pitching.  Intriguing, because relief pitching has changed so much over the course of baseball as we know it.  In fact, the use of relief pitchers has never really stopped changing.  So writers have a lot of fun studying it, analyzing it and telling it.

Among those who have told the story well are John Thorn, Bob Cairns, Bill James and, most recently, Mike Carminati.  In fact, Mike told it so well that he was nominated (twice!) for a Primey.

Mike likes to use a lot of tables in his articles, and I thought it might be fun to see if I could graph a few of them.  With his permission, of course.  So here we go.

First, a simple graph from Bill James’ bullpen essay in his Managers Guide book.  It’s the number of relief appearances per game in each year that has ended in an “0,” updated through the year 2000.

As you can see, the use of relief pitchers has not only grown, it has shown no sign of slowing down.  The decline in 1980 was solely due to the introduction of the designated hitter.  You’d probably see even more relievers per game today if not for the DH.

James and Mike both focus on the use of the leader of the bullpen, the relief “ace.”  The ace is typically used when a game is on the line, sometimes called (a bit inaccurately) a “save” situation.  Let’s look at a graph of the number of total saves per decade of baseball, along with each decade’s saves leader.

So the use of relief pitching has risen dramatically, and so has the role of the relief “ace,” the guy who comes in to close the game when the score is close.  The rise in saves has also shown no sign of slowing down.

You should know that this graph, along with several others, will be included in Will Carroll’s new book, Saving the Pitcher, coming soon to your local Amazon.  Will was nice enough to ask me to contribute some graphs to his book, and I was happy to oblige.

You may have noticed that blip in the 1920’s, when the saves leader jumped ahead of the pack.  That leader was one of the pioneers of relief pitching, Fred (Firpo) Marberry.  It was Firpo Marberry who was first used extensively in save situations, though the practice was forgotten for several decades thereafter.  James calls Marberry “the dog that didn’t bark.”

Manager Bucky Harris invented something new when he used Marberry, who was a protypical righthanded flamethrower, as a closer in 1924, 1925 and 1926.  It’s no accident that the Senators enjoyed three of the best seasons ever during that stretch.

However, Harris didn’t seem to quite understand what he had done.  He famously backed off using Marberry to close the seventh game of the 1925 World Series, turning to Walter Johnson instead (and subsequently losing the Series).  Marberry was later moved to the rotation and became a swingman for the rest of his career, and the relief ace practice laid dormant for several decades.

Of course, the full story of the relief ace is much more complex than that.  In the New Historical Baseball Abstract, James proposed five different types of “relief ace” usage over time, ranging from “entering the game when the starter tires” to “entering the game for only one inning when the team is slightly ahead.”

Mike subsequently analyzed the use of all relievers in baseball history and categorized them according to the James paradigm, putting each pitcher’s season into one of the categories.  He next calculated something kind of complicated, called “pitching runs.”  Pitching runs are the reliever’s ERA vs. the league average, multiplied by innings pitched.  This is the sort of stat that is used elsewhere on this site, as well as many other places (see Lee Sinnins’ Runs Saved Above Average).

Mike took it one step further, however, building on James’ work.  He calculated the game impact of each run saved above average, based on the usage of the pitcher.  If a pitcher was used more often than not in save situations, his runs saved were more valuable because of the critical nature of the innings he pitched.

If I haven’t described that well, you really should read Mike’s work.  Another great place to understand these concepts is Tangotiger’s Leveraged Index.  And go on out and buy the New Historical Baseball Abstract while you’re at it.

Let me plunge ahead and show you a graph of the total pitching runs achieved by relief aces over the last century and a third:

Three things have driven the increase in pitching runs contributed by relief aces.  They have been used more often, they have been used in more save situations, and they have also become better pitchers.  The relief ace of the 1990’s is a much better pitcher than the ace of the 1940’s, relative to other pitchers of the day.

There are differences between the pitching runs graph and the saves graph.  The jump in the 1950’s is more dramatic, and there is even a decline in the 1990’s.  Let’s take the story one step further by looking at a few of the James types.  To make things easier, I’ll just concentrate on the second half of the century.

First, let’s group all pitchers who frequently led their team in saves, but pitched in other situations, too.  They averaged saves per game of .3 to .4, so they were the “ace” of the staff, but they were also used in non-save situations.

Here’s a graph of how much value those types of pitchers contributed in the last half of the century:

Well, those guys came and went, didn’t they?  So what types of usage patterns came along instead?  James labeled another type the “Bruce Sutter” pattern, in which ace relievers were held back for critical appearances.  This was a pattern pioneered by Sutter’s manager, Herman Franks, who wanted to preserve Sutter’s arm.  Let’s add them to the graph:

The Sutters were the trend of the 1980’s, not quite replacing the first set of relief aces in value.  Both types declined significantly in the 90’s, contributing virtuallly no positive pitching runs.  The relief ace role changed dramatically in the 90’s, driven by another James type called the “Robb Nen pattern.”

The Robb Nen pattern is one in which the relief ace only appears in one-inning save situations.  No more or less.  It is the typical pattern of closer usage we see today.  Let’s add it to the graph:

You can see how dramatic this shift has been.  The Robb Nen pattern took hold of managerial strategy in the 90’s, and those pitchers added a ton of value by being used exclusively in save situations.

Still, as our original pitching runs graph showed, 1990’s relief aces in total did not add as much value as they had in the ‘80’s.  Robb Nen types pretty much wiped out the value of all other relief ace types.  Said differently, relief aces only added value in very specific, focused situations in the 1990’s, and their overall impact declined as a result.

To show what I mean, let’s group all five of James’ usage types into one colorful stacked bar chart.

See?  The one-inning Robb Nen pattern has actually decreased the value of relief aces overall.  This, of course, is Bill James’ maligned and misinterpreted point.  He feels, and many other agree, that relief aces could add more value to the team by pitching in more than one inning, or not just when the team is ahead.  Hopefully, these graphs have helped make the point.

So has the bullpen stopped contributing overall?  This article has focused on relief aces, who are the most important but not the only members of the bullpen.  What about all the other relievers, the guys who don’t record saves?  What have they contributed to the cause?  Well, here’s a graph of their pitching runs by decade:

Man, this would take a whole nother article.  Suffice to say that middle relievers have historically been the worst pitchers on a team and that is still true today.  However, over the last two decades, middle relievers have contributed significantly more than in the past.  Guys like Octavio Dotel, Damasco Marte, Brendan Donnelly and Guillermo Mota have filled in the gap left by the Robb Nen closers.

Mike’s observation is that 2003 may, in retrospect, be seen as a turning point in the history of relief pitching.  One in which the use of relief aces, and the bullpen in general, starts to take another turn.  Stay tuned.

Many thanks to the generous Mike Carminati, for sharing his data for this article.  Also, thanks, as always, for the Sean Lahman database.

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