Comments on: Confused Says What?… Getting to Know FanGraphs Stats

By: tangotiger

tangotiger — Thu, 04 Feb 2010 14:57:31 +0000

I see. So, I speculated that if I had 100 Bonds PA at home, that that would NOT be enough. I speculated that if I had 10,000 Bonds PA at home, that it WOULD be enough.

And I asked: when does the switchover happen. And I guessed 1000.

Your response is that my guess is absurd. And you offer no guesses of your own.

We don’t practice US-style politics here. What is your guess?

By: evo34

evo34 — Thu, 04 Feb 2010 09:24:59 +0000

Using player-specific park factors for 1,000 total PA? That’s truly absurd. You have enough experience analyzing data to know better than this.

By: JayCee

JayCee — Sat, 16 Jan 2010 21:47:37 +0000

A question about park effects:

Take Old Yankee Stadium. Because of the short porch in right field, the Yankees specialize in either left-handed pitchers or pitchers who can keep left-handed batters from pulling the ball. Does this mitigate the computed park effect? It’s my understanding visiting team stats are often used, because they are a better sample. So would Yankee Stadium end up looking neutral, and thus the hitting of left-handed Yankes appear to be better than it is, becuase the Yankees batters are not facing specialized pitching staffs?

By: Tonia Nappi

Tonia Nappi — Sat, 16 Jan 2010 19:55:55 +0000

Hi I found this site when i was searching yahoo for this

By: Samuel E. Giddins

Samuel E. Giddins — Tue, 10 Nov 2009 02:08:45 +0000

I think it’s great you actually did it!

By: Hizouse

Hizouse — Mon, 23 Feb 2009 22:42:32 +0000

Thanks!

By: kensai

kensai — Mon, 23 Feb 2009 21:45:57 +0000

Thank you very much, this clears up a ton of confusion for me.

By: David Appelman

David Appelman — Mon, 23 Feb 2009 20:52:02 +0000

The reasoning behind this is that you can’t strike out if you’re not swinging the bat or not getting pitches to actually hit, so K% is per AB and BB% is per PA. The point is to try and isolate ability to make contact with the ball using traditional stats as opposed to actual swing/miss rates.

By: David Appelman

David Appelman — Mon, 23 Feb 2009 20:49:17 +0000

1. wOBA is not park adjusted on the player pages. “Batting” under the player value section is park adjusted wRAA.

2. UZR is absolutely adjusted by position. It’s set up so that it’s based against the average at each individual position, not all the positions combined.

3. Positional run adjustments are based on these: http://www.fangraphs.com/blogs/index.php/confused-says-what-getting-to-know-fangraphs-stats/#comment-55754

Those positional adjustments I linked to are per 162 games, which is what we’re using for the calculations so that’s why he’s at -12.5 for 161 games played (rounded to the nearest .1 on the player page). I see where in the Cameron article it said 150, but that’s now fixed.

It’s based on games and not innings for simplicity and to keep the DH positional adjustment easier to handle.

By: kensai

kensai — Mon, 23 Feb 2009 20:19:19 +0000

I had 3 questions, if you have the time.

> 1. I know wRAA is not park adjusted, but is wOBA park adjusted on a
> player’s page?
>
> 2. I heard UZR is not adjusted by position like Plus/Minus is. Is there
> any truth to that? If so, what is it normalized against?
>
> 3. Positional Adjustment Runs
>
> I’m a bit confused by how these are given out.
>
> In a post by Dave Cameron, he says that the positional adjustments are for
> 150 games played.
>
> Yet, when I look at player page like Adrian Gonzalez, I see that he is
> only given -12.5 runs despite playing in 161 games, starting 159, and
> playing 1417.1 innings. More confusing is that he started 161 games last
> year, played more innings, but was given -12.4 runs positional adjustment.
>
> Is there a cap on the positional adjustments unlike replacement level
> adjustments? Even so, why would Gonzalez get 0.1 more credit for playing
> more innings in 2007 over 2008?
>
> I’m confused by that. Maybe i’m looking at it completely wrong. Thanks in
> advance.