Baseball for the Thinking Fan

Login | Register | Feedback

You are here > Home > Baseball Newsstand > Baseball Primer Newsblog > Discussion
Baseball Primer Newsblog
— The Best News Links from the Baseball Newsstand

Tuesday, November 13, 2012

Camden Depot: Measuring Bullpen Management: Bucking Up the Bullpen

Jon Shepherd suggests a way to evaluate a manager’s bullpen usage over time, drawing on Dan Lependorf’s article at Hardball Times:

A Hardball Times article suggested using WPA - WPA/LI as a measure of bullpen performance that would be useful in assessing bullpen management.  WPA is the acronym for Wins Probability Added.  This is calculated as the difference in win expectancy before and after an event. LI is the Leverage Index.  It is a measurement of how consequential a specific scenario is based on the inning, outs, score, baserunners, and baserunner position.  By using the two statistics in concert, you arguably have a measure that gives you a context neutral wins added metric.

To test whether this metric would give an indication that managers have skill associated with using a bullpen well, I decided to take the last five seasons of several recent managers.  I compare each manager’s mean for WPA, WPA/LI, and WPA-WPA/LI (ANOVA).  WPA will inform us simply if certain teams wind up with better outcomes for winning based on reliever usage.  WPA/LI will neutralize all situations and measure reliever ability in general (similar to wOBA).  WPA-WPA/LI is being used to inform us about whether relievers actually perform better in clutch situations.  If one of these statistics indicate an actual skill then the numbers associated with a manager should be (1) repeatable and (2) result in managers being different from each other.  Of course, this assumes that these things are, in fact, measurable.

The results are somewhat as you might expect: Showalter, Joe Girardi, and Joe Maddon do well, Eric Wedge, Ozzie Guillen and Mike Scioscia do relatively poorly. There are a couple of surprises mixed in - Ron Washington in the upper tier, Bruce Bochy and Jim Leyland near the bottom.

Not a perfect study, but an excellent start.

Mike Emeigh Posted: November 13, 2012 at 09:57 AM | 0 comment(s) Login to Bookmark
  Tags: bullpens, managers, sabermetrics

Reader Comments and Retorts

Go to end of page

Statements posted here are those of our readers and do not represent the BaseballThinkFactory. Names are provided by the poster and are not verified. We ask that posters follow our submission policy. Please report any inappropriate comments.

You must be Registered and Logged In to post comments.



<< Back to main

BBTF Partner

Support BBTF


Thanks to
for his generous support.


You must be logged in to view your Bookmarks.

Hot Topics

NewsblogIt’s Mashiro Tanaka’s time to earn his $175 million | New York Post
(31 - 11:47am, Oct 07)
Last: ReggieThomasLives

NewsblogArrieta-Cole, Objectively One of Best Playoff Matchups Ever | FanGraphs Baseball
(8 - 11:45am, Oct 07)
Last: ERROR---Jolly Old St. Nick

(115 - 11:44am, Oct 07)
Last: Tom Nawrocki

NewsblogOTP October 2015 II: Religion, Politics, Baseball - America's Favorite Pastimes Come Under the Microscope in Shaking the Tree's Gorgeous PASSION PLAY PART III
(42 - 11:43am, Oct 07)
Last: The Good Face

NewsblogProjected Arbitration Salaries For 2016
(5 - 11:42am, Oct 07)
Last: ReggieThomasLives

Newsblog2015 NL Wild Card Game OMNICHATTER
(32 - 11:42am, Oct 07)
Last: Spahn Insane is enjoying a peaty potation

NewsblogMatt Harvey on missing playoff workout: 'I just screwed up' | Newsday
(33 - 11:40am, Oct 07)
Last: SoSHially Unacceptable

NewsblogMarlins' president Samson regrets unorthodox move of GM as manager - Sun Sentinel
(3 - 11:39am, Oct 07)
Last: ReggieThomasLives

NewsblogPrimer Dugout (and link of the day) 10-7-2015
(9 - 11:38am, Oct 07)
Last: Tom Nawrocki

NewsblogBernanke: More execs should have gone to jail for causing Great Recession
(60 - 11:36am, Oct 07)
Last: dlf

NewsblogOT: Soccer October 2015
(124 - 11:16am, Oct 07)
Last: I am going to be Frank

NewsblogThe Cubs Might Have Screwed Themselves By Screwing Kris Bryant
(50 - 11:14am, Oct 07)
Last: Slivers of Maranville descends into chaos (SdeB)

NewsblogIchiro Suzuki signs with Miami Marlins |
(9 - 11:03am, Oct 07)
Last: Ray (RDP)

Hall of MeritMost Meritorious Player: 1910 Discussion
(6 - 10:54am, Oct 07)
Last: Chris Fluit

NewsblogAt 21, Cubs shortstop Addison Russell is a true student of the game - Chicago Tribune
(35 - 10:13am, Oct 07)
Last: Andere Richtingen

Page rendered in 0.1775 seconds
45 querie(s) executed