Comments on: tRA on FanGraphs

By: Dan Novick

Dan Novick — Sun, 16 Aug 2009 19:43:32 +0000

So then FanGraphs wOBA and WAR underrates Pujols! I never thought that was even possible.

By: Pip

Pip — Sun, 16 Aug 2009 17:50:55 +0000

Graham once told me that it simply stood for “the Run Average.” A modest name for such an elegant stat!

By: Lee Panas

Lee Panas — Sun, 16 Aug 2009 15:33:24 +0000

Conceptually, I like that tRA includes batted ball data in the calculation. One of the complaints I hear from traditionalists is that FIP is a “useless” stat because, beyond home runs, it ignores the pitcher’s ability to avoid hard hit balls. We can argue to what degree pitchers have that ability but it’s an issue that always comes up when I try to explain FIP.

On the other hand, I’m not yet convinced that tRA increases the accuracy of ERA prediction enough to make the extra complexity worthwhile. I like that you have it here though because it gives us a chance to study it more carefully side by side with FIP. So, thanks for the addition.

By: Andy S

Andy S — Fri, 14 Aug 2009 20:35:36 +0000

Really? I don’t understand…maybe I don’t understand how the regression is taking place, but isn’t it that you can throw in xRuns at the league average tRA and average that in?

By: David Appelman

David Appelman — Fri, 14 Aug 2009 20:20:00 +0000

Does it really include intentional walks in wOBA? Does it use the same denominator and the exact same method of converting wOBA into wRAA (or bRAA on statcorner?)

The nice thing about not including IBBs in wOBA is that when you convert to wRAA using plate appearances you get a custom value for IBBs that is the average value of a plate appearance for that particular player. The value of an IBB is very different from player to player.

By: Teej

Teej — Fri, 14 Aug 2009 20:05:31 +0000

Yay!

By: Jeff Sullivan

Jeff Sullivan — Fri, 14 Aug 2009 19:03:37 +0000

The regressed version is ohmygod annoying to program.

By: marcello

marcello — Fri, 14 Aug 2009 19:03:31 +0000

I always assumed it stood for True Runs Allowed, but I have no clue if that is correct.

By: Jeff Sullivan

Jeff Sullivan — Fri, 14 Aug 2009 19:02:00 +0000

In addition to what Colin said, Statcorner includes RBOE and adjusts for things like intentional walks and sac bunts.

By: Graham

Graham — Fri, 14 Aug 2009 19:01:10 +0000

Statcorner uses reached base on error as part of wOBA and does not use SB/CS