FanPost

WPA vs. wRAA

I'm looking at the difference between WPA and wRAA as a tool for measuring leverage. 

Background: I've got a coworker who has argued that Ichiro's hits come "when they don't matter."  I don't believe this is true and I'd like to test the hypothesis.  I think the best way to do this is WPA vs. wRAA.  My understanding is that wRAA is a straight linear-weights, context neutral stat that includes plate appearances, stolen bases, and caught stealing.  WPA only uses the same events, but is entirely context-dependent.  Taking the difference between the two should yield an answer on whether a player's contributions come in low-leverage moments.

I'm using Fangraphs as my data source, because they're awesome.

However, I have a couple of questions on the use of these stats to make sure that I'm doing this properly.

First: Do they, in fact, cover the same events?  (Or so close that I can get away with it.)

Second:  Which wRAA do I use?  There's the wRAA that's listed as such on Fangraphs, but then there's the batting component of WAR listed at the bottom of the page.  They're different, and it looks like the batting component of WAR is park-adjusted; should I use that?

Third: What's the conversion factor?  I know that +10 wRAA = 1 win.  And +0.50 WPA = 1 win.  So 10 wRAA = 0.50 WPA, and I can work the conversion from there, yes?  But then I start going around about the math and wonder if +10 wRAA gets you from 81-81 to 82-80, and is thus worth +1.00 WPA.  (And I'm aware that 10 runs = 1 win is a convenient abstraction, and the actual run value varies a bit from year-to-year.  And I'm wondering if that's significant enough that I need to account for it, or if I can use the standard 10 runs = 1 win.)

Or, am I attacking this problem from an entirely wrong angle, and there's a better way to do the analysis?  (Or even someone who's done the legwork for me, and I can point to the results?)

Thanks in advance for the help with the questions.

X
Log In Sign Up

forgot?
Log In Sign Up

Please choose a new SB Nation username and password

As part of the new SB Nation launch, prior users will need to choose a permanent username, along with a new password.

Your username will be used to login to SB Nation going forward.

I already have a Vox Media account!

Verify Vox Media account

Please login to your Vox Media account. This account will be linked to your previously existing Eater account.

Please choose a new SB Nation username and password

As part of the new SB Nation launch, prior MT authors will need to choose a new username and password.

Your username will be used to login to SB Nation going forward.

Forgot password?

We'll email you a reset link.

If you signed up using a 3rd party account like Facebook or Twitter, please login with it instead.

Forgot password?

Try another email?

Almost done,

By becoming a registered user, you are also agreeing to our Terms and confirming that you have read our Privacy Policy.

Join Lookout Landing

You must be a member of Lookout Landing to participate.

We have our own Community Guidelines at Lookout Landing. You should read them.

Join Lookout Landing

You must be a member of Lookout Landing to participate.

We have our own Community Guidelines at Lookout Landing. You should read them.

Spinner.vc97ec6e

Authenticating

Great!

Choose an available username to complete sign up.

In order to provide our users with a better overall experience, we ask for more information from Facebook when using it to login so that we can learn more about our audience and provide you with the best possible experience. We do not store specific user data and the sharing of it is not required to login with Facebook.

tracking_pixel_9351_tracker