THE BOOK--Playing The Percentages In Baseball

As we’ve discovered in The Book, the batter gets the advantage over the pitcher each time they face each other in the same game.  The advantage is 8 points in wOBA (which is 8 OBP and 10 SLG, or 18 OPS).

Here’s Pedro’s career (OPS of .597)
http://www.baseball-reference.com/pi/psplit.cgi?n1=martipe02

.590: 1st PA in game
.590: 2nd PA in game
.613: 3rd+ PA in game

Doesn’t seem like his arm falls off.  Here’s via pitch counts:
101st+ pitch: .606

Of course we’re going to hear about 2003:
http://www.baseball-reference.com/pi/psplit.cgi?n1=martipe02&year=2003

And his 53 PA on the 101st and later pitch (OPS of .705, still better than league average).  As we know, 53 PA means almost nothing, unless you have reason to believe, prior to seeing the data, that he’s subject to collapse.

His 2002 data is all over the place, and his 2004 data shows his performance improving.

The decision to pull him or not in that Game 7 had zero to do with his 53 PA of that season, and had everything to do with what the manager was interpreting what he was seeing.

We should adjust by age of course, but here’s a starting point…

Dante Bichette:
137 HR in 2293 PA (Coors, Mile High)
137 HR in 4563 PA elsewhere

The math is real easy here.  That’s double the output.  Or a jump of 18 HR per 600 PA.

Juan Pierre:
1 HR in 835 PA (Coors)
11 HR in 3680 PA elsewhere

Coors no help here, actually a drop of 1 HR per 600 PA.

Larry Walker:
155 HR in 2531 PA (Coors, Mile High)
228 HR in 5499 PA elsewhere
105 HR in 2531 PA elsewhere, prorated

So, 50% pop for him, or a jump of 12 HR per 600 PA.

Todd Helton:
176 HR in 3134 PA (Coors)
110 HR in 2952 PA elsewhere
Similar change to Walker.  Both lefties, both excellent hitters.

Each park affects each type of player differently.  Doesn’t make any sense to pretend otherwise, with the silly single-unit park factors.

From 1993 to 2006, there were 22 HR hit per 600 PA in Coors+Mile High, and 16 when the Rox played on the road.  That’s a difference of 6 HR per 600 PA, or 38%.

It’s very possible that Walker and Helton were ideally suited to take advantage of the HR-tendency of the park, while Bichette was insanely suited to do so, while Juan Pierre was irrelevant.

A serious study on the issue would classify all players who’ve ever played at Coors by their style (left/right, aggressive/patient, GB/FB, Rox player or not, etc), so that the appropriate adjustment (both as a rate and as a differential) can be determined.

Where is the link to sign up for the $29 service?

Uhm, good point.

I’m already logged in, so I don’t see the subscribe button.  And, I don’t see any way to logout (other than clearing my cookie).  The logout button should be on every page.

But, if you go to:
http://www.baseball-reference.com/pi/
And try to run a report, it’ll come up with a partial list, and then ask you to subscribe if you want all the features of PI (play index).

For such a well-designed site, kinda weird that the “subscribe” button is not featured more prominently (like, on every single PI page), especially since it’s money in Sean’s pocket.

Yeah, I had no idea the subsribe section even existed.  I am more than happy to do so, even if it offered no extra content, as a day barely goes by that I don’t use B-R.

As far as well-designed, I don’t know. I am not too partial to sites that are cluttered, confusing, and are not easily navigated. For example, I think that BTF is a complete disaster of a site to navigate. Then again, I am old and cranky when it comes to those things.

Sean put up a SUBSCRIBE button at the top of the page in my link in post #5.

BTF is a disaster.  The good ole days of Primer are long gone.

Tom - Few questions about fangraphs

What are these statistics? +WPA, -WPA, REW, pLI, phLI, PH.

Thanks in advance.

I don’t have any problem with the content on BTF.  To me it is the same as the old Primer.  It is the layout I can’t stand.  Who the hell knows what a blogpen, newsstand, old-school newsstand, etc. is?  Why can’t we speak English anymore on these web sites?  They should be geared towards the lowest common denominator of users.  For example, I don’t even know anymore how to get to the “sabermetric studies” section without trying almost every link.

BRAA: delta runs, REafter minus REbefore ... classic LWTS by the 24 base/out states

REW: is BRAA/10.x ... that is runs divided by something to get it into wins

LI: leverage index ... the pLI refers to the average for each PA ... the phLI refers to the average for each pinch hit appearance ... click on ARTICLES at the top of this page, under the banner, and read the third Leverage Index article

+WPA: win advancement (WA)… just the positive contributions to increase win expectancy

-WPA: loss advancement (LA)… just the negative

WPA: WA - LA

So, Pujols’ WA is 18 wins, and his LA is 9 wins… his WPA is +9 wins above average.

Further to my post#2:

By my quick count, since the year 2000, Bonds has hit 151 HR on the road, and 155 at home.  John Beamer however applies a “standard” HR park factor:
http://www.hardballtimes.com/main/article/is-barry-bonds-really-the-home-run-king/

I don’t know when the regression point is 50% (that is, at what point are Bonds’ HR park splits at the r=.50 mark?), but my guess is that he’s way past it.  How Pac Bell, AT&T or whatever the park is called, has affected the “average” MLB hitter means little based on the number of PA Bonds has amassed there, as well as what we know about Bonds (he hits ‘em real far).

I wouldn’t presume that Bonds would hit more HR if he were at an “average” park.