From: tedward@cs.cornell.edu (Edward [Ted] Fischer)
Subject: Re: Statheads and park effects
Organization: Cornell Univ. CS Dept, Ithaca NY 14853
Date: Mon, 21 Dec 1992 03:33:22 GMT

In article <28591@optima.cs.arizona.edu> dkl@cs.arizona.edu (David K. Lowenthal) writes:
>
>Before last season, several netters and I engaged in a "discussion" of
>how Greg Swindell would do with the Reds.  He came from a huge park,
>Cleveland, and went to a homer haven, Riverfront.  He posted an upper
>3's ERA with Cleveland the previous year.  I was scorned, especially
>by Valentine, when I suggested his stats might improve because he was
>playing for a better team, even though the park effect would suggest
>a downward trend.  Netters predicted a mid 4 ERA for him given the 
>park change and his tendency to give up homers.  He ended up with
>a mid to high 2's ERA.

Yah.  Egg on my face!  ALWAYS in the past was Swindell homer-prone.
In 1990 and 1991, he allowed a total of 48 HR in 452 IP.  One year
(1987), he allowed 18 HR in only 102 IP!

Last year Swindell allowed only 14 HR in 213 IP, the best HR/IP ratio
of his career.  Nothing else really changed.  He wasn't suddenly
striking out more batters or allowing fewer hits.  He didn't walk more
or fewer guys.  He simply cut down on those souvenirs.

I was betting on 30 HR...  Boy was I wrong!  (Though did I really
predict a mid-4s ERA?  Seems a bit extreme, considering the move to a
no-DH league.)

>Obviously this is only one example.  But all i am asking is can you throw
>around park effects like they are gospel?  What percent of your predictions
>are correct?

I dunno.  Never tried to figure this one out.  To a certain extent,
park effects are important to judge the *value* of a performance.  A
3.60 ERA is more valuable in Fenway than in Houston, because it will
win you more games.  But the predictive aspect is somewhat harder to
test (and is generally based less on statistics than on other
factors).

>Players can adjust to new surroundings, and stat people
>don't consider that.  These kind of things are called "intangibles", 
>or *luck* by Ms. Nichols.

Bullshit.  Nobody calls them intangibles or suggests that they are due
to luck.  (Okay, so you just called them intangibles.  But that's not
what most people mean by the term, and I've *still* never heard
anybody suggest that this is "luck".)

>For example, can't a pitcher who just pipes
>the ball because he pitches in the Astrodome start nibbling the corners
>when he gets traded to Riverfront?  Can't a hitter who hits 20 homers
>in Oakland take one look at the short Yankee porch and hit fewer homers
>because he wants to pull everything (cf. Dave Revering)?

Yes, this can happen.  But for the most part, players don't have that
much control over how they play.  They tend to learn a certain style
in high school and the minors, and they stick with that throughout
their major league careers.  Radical changes in style *will* lead to
radically different results.  Frank Howard jumped from being a very
good hitter to a totally dominant force, after a talk with Ted
Williams changed his approach at the plate...  These things are, of
course, impossible to predict and so *no* prediction is going to
reliably take them into account.  (Though kudos to you for predicting
Swindell, whether or not your reason was correct...  It didn't seem to
me like he was blazing it down the pipe any less, but I didn't see him
much.)

An interesting case for next year...  Wade Boggs has just moved to
Yankee Stadium.  As you all know, Boggs has always been a dead LF
hitter with the Red Sox.  Even on the road, he slaps the ball towards
where the Wall "should" be.  Now that his home park is Yankee Stadium,
will he change his approach?  If he continues to push the ball to LF,
he will put up *awful* numbers.  If he learns to pull, he could have a
20 HR season...

Any predictions here?  I believe most of his HRs have always been to
right field (though most of his 2Bs are to LF, of course).

Cheers,
-Valentine
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