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

Sunday, April 20, 2014

Studeman: Why wOBA Works

Why wOBA Works

Let’s say you have a player, let’s call him Al Trout, who has hit six singles in 10 plate appearances (making an out every other time) and the league, on average, hits three singles every 10 plate appearances (again, making an out every other time). To use linear weights to figure out how many more runs Al contributed above the league average, you’d…

  Calculate the extra runs Al contributed by hitting more singles, which equals the difference in singles times the run value of a single, or (6-3) times 0.48, or 1.44.  Then you’d…
  Calculate the extra runs that Al contributed by making fewer outs, which equals the difference in outs made times the run value of an out, or (4-7) times -0.30 (that’s a negative 0.30), or 0.9. Then you’d…
  Add the two together. 1.44 plus 0.9 equals 2.34. In his 10 plate appearances, Al contributed 2.34 runs more than the average player.

Okay, I have to add a technical footnote here. I have shown you this way of calculating linear weights because it will make it easier to understand the wOBA formula But, in reality, you only have to multiply Al’s singles and outs by the appropriate linear weights of that league and year to calculate the number of runs he contributed above average.

Anyway, that’s the hard linear weights way to calculate the difference.  Here’s the wOBA way:

  Multiply the difference in singles times the wOBA multiplier, or (6-3) times 0.78, or 2.34.

That’s it; one simple step. wOBA shows that Al contributed 2.34 runs more than the average player, the same outcome as the linear weights.

Why does this happen? Because wOBA weights include the impact of the hit AND the impact of turning an out into a hit. When you keep the number of plate appearances even, you’re not just adding a hit to the hit total.  You’re also reducing an out from the out total. wOBA captures the impact of both event changes.

wOBA fundamentally works because it is a rate stat.  Its divisor is plate appearances. When you compare two players’ wOBA you have equalized their total plate appearances.

Thanks to Los.

Repoz Posted: April 20, 2014 at 05:27 AM | 1 comment(s) Login to Bookmark
  Tags: 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.

   1. Walt Davis Posted: April 21, 2014 at 06:09 PM (#4690582)
wOBA is just oRAR/PA, pointlessly (and incorrectly) re-scaled to an OBP-like measure. (or the hitting-only component of oRAR if you don't want to include baserunning) That's it, nothing special.

You must be Registered and Logged In to post comments.

 

 

<< Back to main

BBTF Partner

Support BBTF

donate

Thanks to
danielj
for his generous support.

Bookmarks

You must be logged in to view your Bookmarks.

Hot Topics

Newsblog2014 WORLD SERIES GAME 2 OMNICHATTER
(43 - 8:00pm, Oct 22)
Last: Into the Void

NewsblogOT: Politics, October 2014: Sunshine, Baseball, and Etch A Sketch: How Politicians Use Analogies
(3147 - 7:59pm, Oct 22)
Last: Misirlou's been working for the drug squad

NewsblogHunter Pence responds to Royals fan signs with monster Game 1 | MLB.com
(54 - 7:50pm, Oct 22)
Last: JE (Jason)

NewsblogStatcast: Posey out at the plate
(11 - 7:49pm, Oct 22)
Last: Merton Muffley

NewsblogMike Scioscia, Matt Williams voted top managers
(43 - 7:45pm, Oct 22)
Last: catomi01

NewsblogHow Wall Street Strangled the Life out of Sabermetrics | VICE Sports
(5 - 7:40pm, Oct 22)
Last: Merton Muffley

NewsblogJay set for surgery — and for CF in 2015 : Sports
(2 - 7:28pm, Oct 22)
Last: JJ1986

NewsblogSielski: A friend fights for ex-Phillie Dick Allen's Hall of Fame induction
(173 - 7:28pm, Oct 22)
Last: Sunday silence

NewsblogRoyals are not the future of baseball | FOX Sports
(28 - 7:11pm, Oct 22)
Last: Belfry Bob

NewsblogDealing or dueling – what’s a manager to do? | MGL on Baseball
(39 - 7:10pm, Oct 22)
Last: bobm

NewsblogOT: The Soccer Thread, September 2014
(873 - 7:02pm, Oct 22)
Last: Jose Is The Most Absurd Thing on the Site

NewsblogJerome Williams re-signs with Phils
(6 - 6:36pm, Oct 22)
Last: Brian White

NewsblogHitting coaches blamed for lack of offense - Sports - The Boston Globe
(18 - 5:40pm, Oct 22)
Last: Bhaakon

NewsblogBaseball's hardest throwing bullpen - Beyond the Box Score
(11 - 5:31pm, Oct 22)
Last: Walt Davis

NewsblogOT: Monthly NBA Thread - October 2014
(339 - 5:16pm, Oct 22)
Last: Merton Muffley

Page rendered in 0.2024 seconds
52 querie(s) executed