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
Eugene Freedman
for his generous support.

Bookmarks

You must be logged in to view your Bookmarks.

Hot Topics

NewsblogOTP - July 2015: Winning the Political Game: Politics is More Like Baseball Than Football
(612 - 6:28pm, Jul 04)
Last: David Nieporent (now, with children)

NewsblogOT: Soccer June 2015
(917 - 6:22pm, Jul 04)
Last: The Anthony Kennedy of BBTF (Scott)

NewsblogWho is baseball's best manager? The survey says ...
(10 - 6:08pm, Jul 04)
Last: Morty Causa

NewsblogOT: Monthly NBA Thread - July 2015
(463 - 6:04pm, Jul 04)
Last: Los Angeles El Hombre de Anaheim

NewsblogTrevor Bauer imitates teammates batting stances during an at-bat.
(1 - 6:00pm, Jul 04)
Last: pthomas

Newsblog7-4-2015 OMNICHATTER
(49 - 5:12pm, Jul 04)
Last: The Yankee Clapper

NewsblogDeford: All-Star Games Are Worthless If The Players Are Not All-Stars
(89 - 4:53pm, Jul 04)
Last: Ray (RDP)

NewsblogMLB and the Grateful Dead - JOIN US FOR THE FINAL 5 SHOWS EVER!
(214 - 4:29pm, Jul 04)
Last: simon bedford

NewsblogCharges pending in alleged St. Louis Cardinals computer intrusion of Houston Astros - CNNPolitics.com
(5 - 4:18pm, Jul 04)
Last: SOLockwood

NewsblogKlapisch: Mets’ 16-13 win over Braves in 1985 an instant classic
(7 - 4:01pm, Jul 04)
Last: RMc is organizationalwide!

NewsblogAlex Rodriguez, New York Yankees settle dispute over bonus payment
(11 - 3:56pm, Jul 04)
Last: Danny

NewsblogTigers place Miggy on DL with calf strain | MLB.com
(8 - 3:30pm, Jul 04)
Last: Crosseyed and Painless

NewsblogBrewers bullpen catcher eats 23 cheesesteaks, breaks Citizens Bank Park record | MLB.com
(33 - 2:38pm, Jul 04)
Last: Der-K is now fully whelmed!

NewsblogCardinals fire Scouting Director for hacking Astros
(70 - 2:09pm, Jul 04)
Last: base ball chick

NewsblogAlex Rodriguez of New York Yankees getting the baseball from his 3,000th hit after all
(3 - 1:59pm, Jul 04)
Last: Shibal

Page rendered in 0.1569 seconds
48 querie(s) executed