Baseball for the Thinking Fan

Login | Register | Feedback

btf_logo
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 10:57 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

donate

Thanks to
Adam M
for his generous support.

Bookmarks

You must be logged in to view your Bookmarks.

Hot Topics

NewsblogOT: The Soccer Thread August, 2014
(1003 - 3:54pm, Sep 02)
Last: Swedish Chef

NewsblogNewsweek: Can Baseball Get More Interesting to Watch With Big Data?
(5 - 3:51pm, Sep 02)
Last: Random Transaction Generator

NewsblogTrevor Hoffman's Hall of Fame induction seems inevitable
(68 - 3:51pm, Sep 02)
Last: zonk

NewsblogMets call up Dilson Herrera, have "talked about" d'Arnaud to LF
(49 - 3:50pm, Sep 02)
Last: The District Attorney

NewsblogPrimer Dugout (and link of the day) 9-2-2014
(35 - 3:50pm, Sep 02)
Last: Ok, Griffey's Dunn (Nothing Iffey About Griffey)

NewsblogOT: Politics, September, 2014: ESPN honors Daily Worker sports editor Lester Rodney
(216 - 3:48pm, Sep 02)
Last: Davo Dozier

NewsblogOT: Monthly NBA Thread - September 2014
(12 - 3:46pm, Sep 02)
Last: andrewberg

NewsblogThe indisputable selfishness of Derek Jeter
(9 - 3:45pm, Sep 02)
Last: The Yankee Clapper

NewsblogRule change means more players to choose from for postseason roster
(8 - 3:43pm, Sep 02)
Last: RoyalsRetro (AG#1F)

NewsblogGleeman: Twins ask fans which brand of luxury car they are
(2 - 3:36pm, Sep 02)
Last: Robert in Manhattan Beach

NewsblogBPP: Why do people still think Jack Morris pitched to the score?
(24 - 3:21pm, Sep 02)
Last: JL

NewsblogBrewers prospect plays every position, all in one game
(10 - 3:17pm, Sep 02)
Last: zonk

NewsblogOT August 2014:  Wrassle Mania I
(103 - 3:16pm, Sep 02)
Last: Good cripple hitter

NewsblogPhoto of the day: Bill Murray, indy league ticket-taker
(119 - 3:15pm, Sep 02)
Last: GGC don't think it can get longer than a novella

NewsblogExtreme Moneyball: The Houston Astros Go All In on Data Analysis
(8 - 2:58pm, Sep 02)
Last: Ron J2

Page rendered in 0.1711 seconds
50 querie(s) executed