THE BOOK--Playing The Percentages In Baseball

Tuesday, June 10, 2008

Trueer-ish Park Factors

Brian gives us his park factors, which includes various climate parameters…

Tuesday, May 27, 2008

Craig Wright, Coors, and the Humidor

A Craig Wright sighting (hat tip: HardballTimes):

They calculated that a home run swing, one that would drive a mid-range ball (5.125 ounces and 9.125 inches in circumference) 387 feet, would go 421 feet if it were the smallest legal ball and 372 feet if it was the largest legal ball. That’s an incredible difference. Two perfectly legal balls could differ almost FIFTY feet on the same home run swing. (I suppose that impact is mitigated somewhat in actual practice by the pitcher being able to throw the smaller ball slightly faster as well.)

Wright worked for the Rox for a period of time.

Friday, May 23, 2008

Size of parks and talent: Be careful about what you are pretty sure is true…

Almost no one, even analysts you read on THT, BP, and other sabermetric columns, blogs, and web sites, does not think that fly ball pitchers or pitchers who give up a lot of HR’s (pretty much the same animal, I think) fare better in stadiums in which it is difficult to hit a home run, and have no business pitching in a stadium that allows a lot of HR (present company excepted).  Remember the hullabaloo when Cincinnatti signed Eric Milton, a fly ball and home run machine?

I have for years tried to prove that that CW is true and have thus far failed.  In fact, I have never subscribed to that theory.  I don’t subscribe to any theory unless there is some (credible) evidence that it is true.  Nor have I ever subscribed to the commonly accepted (again, even in analytical circles) theory that fast or good outfielders far better in larger outfields, and ditto for small outfields and slow defenders (you know, the old axiom that in a large OF, you need fast outfielders and in a small outfield, you don’t).

Well, these things appear to make intuitive sense, but like a lot of things in baseball and in life, appearing to make sense does not the truth make.  If that were the case, all of the talking heads would be geniuses and we, the skeptics and seekers of the truth, would just be drinking diet coke in our mother’s basements.

Anyway, has anyone ever (I mean ever) seen any proof or evidence that either of these propositions is true?  I haven’t, and I have read as much sabermetric research as anyone I would think (since I don’t really have anything better to do).  That is especially true of proposition #2, that of the fast and slow outfielders.

I did a study looking at the issue, using outfield size in square feet, speed ratings on OF’ers, and UZR.  I did a preliminary study which seemed to show that CW was right and that speedy outfielders did “more better” than slower ones in large outfields, as compared to small ones.  However, I looked at entire outfields and did not break them down into left, center, and right (so that left field at Fenway was treated the same as CF and RF (it is a small outfield, all together) and I did not look at that many years (I used a small sample).

Later on, I increased the sample size and broke down each outfield into left, center, and right.  A much better study of course.  I don’t think I ever published the results, although I might have mentioned it, but there was some evidence that a faster outfielder did comparatively better in a small outfield.  I don’t know why, or if the results were significant, but there was definitely no evidence that a large outfield requires a speedy outfielder.  No evidence at all.  In fact, as I said, the evidence, for some reason, suggested the opposite.

Getting back to the first proposition, that you don’t want a flyball/home run prone pitcher in a “small” stadium (one with a high HR PF), that would probably be true if HR park factors were multiplicative.  In other words, if a batter or pitcher who allowed 6 HR per 500 PA pitched in a park that had a HR PF of 1.5, he would give up or hit 9 HR, and if a player had a HR rate of 20, he would allow or hit 30 in this same park.  But that is apparently not the case.  Tom Tippett in a SABR convention a few years ago, did a nice presentation in which he showed that HR PF are likely a combination of multiplicative and additive.  IOW, the 6 HR player might get a 25% boost in that 1.5 HR PF park and an additional 2 HR, for a total of 9.5, and the 20 HR player would also get a 25% boost plus an additional 2 HR, for a total of 27.  So the 6 HR guy’s HR rate increases by 58% while the 20 HR guy has only a 35% increase.  I made up the numbers, BTW.  I don’t know the proper percentages and additions.

In other words, it is probably NOT true that a high HR pitcher fares really poorly in a high HR park.  In fact, it might be the other way around.  The low HR pitcher might do worse, comparatively speaking.

What brought this whole thing up was that I came across an old and very good article/analysis on BP by James Click that looked at extreme GB and FB pitchers and how they were affected by various component park effects, including HR.  The hypothesis was that since most park factors have to do with fly balls, that the fly ball pitchers should be affected more than the ground ball pitchers in many of these component PF’s. Guess what he found?  Virtually no difference in how extreme FB and GB pitchers are affected by component park factors.  He was surprised.  I was not.  As I said, I have been trying to find out what types of players (other than L/R), batters and pitchers, do better in the various parks, and I have pretty much struck out across the board.

Towards the end of the article, Click says this:

With GB/FB ratio appearing to have no effect on park factors, we must concede that the other unique aspects of each park--weather, hitting background, surface, altitude, etc.--cause similar amounts of variance for both types of pitcher.

Anyway, the moral of the story is to be really careful about accepting as the gospel that which we hear all the time, even when it comes from reliable sources whose intelligence and integrity we respect, and even if it really, really, seems to make sense.

Monday, May 12, 2008

Quick Park Factors

This idea stemmed from the original Historical Abstract.  Here’s what I wrote to David at Fangraphs, and I’ll provide further commentary:

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Friday, March 28, 2008

True HR Park Factors (or at least something we can regress towards)

Here is what I did.  I took each ballpark and recorded the fence height and distance for the LFL, LF, LCF, CF, RCF, RF, and RFL.  LF and RF were around 17 degrees (the whole outfield from line to line is 90 degrees) from the lines and LCF and RCF were around 23 degrees from the lines.

Then I looked at how many HR’s are hit within 8 degrees (4 degrees on either side) of each of the above lines.  As it turns out, of all HR’s hit to either side of the field, around 10% are hit to CF (I used “within 8 degrees left of center” for the “left side CF HR’s,” and “within 8 degrees right of center” for the “right side CF HR’s"), 21% to RC and LC, 24% to LF and RC, and 16% down the lines.  These percentages do not add up to 100 because I only looked at HR’s within around 8 degrees of each line.  I used these percentages for a weighting, as you will see in a minute.

Next I looked at, for each park, a fly ball distance factor, which is basically average home fly ball distance divided by average road (plus a fraction of home) fly ball distance.  This is just like a regular HR or run park factor, only using fly ball distances.  I computed a left side and right side fly ball distance factor.  I used STATS data and included all air balls other than bunts.  For indoor parks or semi-indoor, like Toronto, I used the same number for the left and right sides (the average of the two).  For all other parks, I regressed the right and left side factors 50% toward that park’s overall (left and right combined) factor.  Obviously I only used data for as long as the park was in existence, up to 5 years at the most.  For Coors Field, I used 06 and 07 only, as 06 was the year they started to use the “mega-humidor.” BTW, the fly ball distance factor at Coors went down considerably in 03 (from 1.072 to 1.025) and then again in 06 (to 1.013), so please don’t let anyone tell you that the humidor in 03 and the “mega-humidor” in 06 has had little to do with decreased run scoring and especially HR rates in Coors Field,

Now that I have all the data I need, here is what I did:  I took each fence distance at all of the points mentioned above (4 on the left side and 4 on the right side, double counting CF) and adjusted for fence height.  To do that, I simply added any fence height above average to the fence distance.  I don’t know if that’s right, but I recall that in one of Greg R’s articles on home runs distances, he mentioned that if you add a foot of fence height, you need about another foot of distance on a fly ball to clear that extra foot of fence height.  If I got that wrong, or he has updated that, I am hoping he will respond so I can change this part of the calculations.

Anyway, then I divided by the fly ball distance factors explained above.  This gives us the “effective” or normalized distance for each of those sections of the field.  For example, Coors Field is 347 feet down the left field line (LFL) and the fence is 8 feet high.  The average fence along the LFL is 10.5 feet (Fenway jacks up the number), so we add 2.5 feet to the 347 feet to make it 349.5.  Now we divide by Coors’ left side FB distance factor, which is 1.019 (for 06 and 07).  We divide because a FB factor above 1.000 means that the ball travels further than at an average park, thus the “effective” fence distance is shorter.  That gives us 343 rather than 349.5.

We do the same thing for all 4 points or sections on the left side and then for the right side.  Then we get a weighted average of all 4 sections on each side, weighting by the percentage of HR’s that are hit in that section, the 16, 24, 20, and 10 numbers I explained above.  That gives us a weighted average effective fence distance for the left side of each park and for the right side.  Now we can simply compare this to the averages for all parks by subtracting one from the other.

I actually did the above calculations combining all the parks in both leagues, even though the fly ball distance factors are mostly (I included inter-league games in the data) relative to league (NL or AL) averages.  In any case, here are the results for each park.  A negative number means that the effective average fence distance, assuming the same or league-average height, is shorter than average, and thus the true HR park factor should be greater than 100.

Maybe someone can post how to convert this into an actual HR park factor.  In other words, if a park is -8 on the left side, like Fenway is (as compared to the average NL and AL park), that means that its average fence is 8 feet shorter on the left side.  How would that translate into a park factor?  How many more HR’s (and thus how much more in percentage terms) would be hit if an average park shortened their fences by 8 feet?  Tango did this kind of conversion, I think, when he was discussing major versus minor league baseballs.

I’ll actually post 2 sets of numbers for each park:  One, as compared to all parks in both leagues and one as compared to parks in the same league only.  Keep in mind that I am using the same fly ball distance factors for each set of numbers.  It is likely that they wouldn’t be all that different if we were able to do them relative to all parks and not just mostly parks in the same league.

Also keep in mind that these are only referring to effective fence distances.  They would be more closely connected with HR rates per BIP, or better yet, per FB, rather than per game, inning, or even per PA.  For example, Oakland’s “effective” fences are shorter than average, but because of the large foul territory, many of the PA’s end in a foulout and therefore the HR per PA rate is much less than you would expect from the effective fence distances.  Park factors for K and BB rates have a similar effect.  And of course, these numbers assume the same geographical distribution and ratios of HR/FB/GB at all parks.  It could be that pitchers and/or batters try and pitch or hit towards favorable sections of the OF or in ways that induce more or fewer fly or ground balls.  It would be interesting to compare these numbers to each park’s HR rate per BIP or per FB compared to league averages.  Anyone have that data handy?

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Wednesday, March 12, 2008

Impact of Temperature

Cool article by Jonathan Hale.  He gives you the breakdown of BA, OBP, SLG by temperature, and then, he also shows you the differing movements of pitches by temperature.  Consider this a first-pass, since it doesn’t seem like he controlled for the different pools of players in each temperature group.  It’s a necessary step.  We can presume for the moment that each group is fairly random, but we need confirmation of that.

Tuesday, January 29, 2008

MGL Component Park Factors

Google Docs.

Thursday, January 10, 2008

Wanna do some peer review?

Some academics don’t like us.  Others though appreciate our no holds barred approach.  I firmly believe that any punch above the belt is a fair punch.  Of course, once the guy is down, you back off.  (I hate those old hockey brawls where the guy would pin someone to the ice, and still keep punching the guy.) If you can offer criticism in an honest manner, without personally insulting someone, I think it’s fair.  You might come off as arrogant, or rough around the edges, but those are things that the reader can get past.  Respect, and quality of content.  That said, I got an email:

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Friday, November 30, 2007

Google Earth meets Retrosheet

Philip (Flip) Kromer writes:

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Friday, October 19, 2007

Home Field Advantage

I posted this elsewhere, so I figure I’ll post it here too.  Derived since 1994, using
http://www.baseball-reference.com/games/situational.shtml

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Thursday, July 26, 2007

Should high HR pitchers pitch in low HR parks?

Buster Olney wrote this the other day (on ESPN.com):

“Livan Hernandez,” said a talent evaluator Saturday evening. “I’m surprised that nobody’s talking about him, because he’s out there [on the trade market].”

O.K., let’s fortget about the fact that this “talent evaluator” should probably be evaluating HIS talent as an evaluator, and that no one is talking about Livan because Livan sucks at this point in his career.

“The light bulb goes on: great postseason experience, minimal financial obligation (he’s making $7 million this season, and his contract runs out at the end of this year), a guy who has always taken the ball (nine straight seasons of 30 or more starts, and he’s got 20 starts so far this year). He is not an ace, he gives up a lot of hits, but he will generally keep a good offensive team in games.”

Let’s also forget about Olney writing that “he will generally keep a good offensive team in games.” (Isn’t that true about any bad pitcher?)

“The D-backs are fading, have the minor league arms to take his spot in the rotation for the last two months—and Livan is not really a good fit for them now, anyway, because he is not a shut-down kind of pitcher and they are struggling to score runs. The cost of trading for Hernandez would presumably not be that high.”

More garbage from Olney.  Fading?  Last time I looked, they were 1.5 games out of first!  Struggling to score runs and he is not a shut-down pitcher?  I don’t have to tell anyone on this blog that a good pitcher is good for any team and a bad pitcher is bad for any team, regardless of their ofense, although I suspect that there are minor differences in the value (above or below replacement) of a pitcher depending upon his team’s offense.

“He makes a lot of sense for a team like Atlanta, or a team like the Mets (where he could team with his brother, Orlando), or maybe the Phillies, although he would give up a lot of homers in their park.”

More garbage, but what I want to talk about is the last part of this sentence.  Do pitchers who give up a lot of home runs do worse in a home run park (than other pitchers or as compared to a neutral or low HR park)? 

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Wednesday, July 18, 2007

Ballparks

Just found this site:
http://www.andrewclem.com/Baseball/

Thursday, April 26, 2007

Why do stadiums have illegal dimensions?

Derek points out something interesting about park configurations.

Yes. But the Commissioner allows them to do it. While many parks have their fences at the minimum required distance, the last wave of ballparks had many that violated the space requirements:
- AT&T Park
- Minute Maid Park is 315 feet down the left-field line
- Oriole Park at Camden Yards is 318 feet down the right field line
- Petco Park is 396 feet to center field and 322 feet to right field
- PNC Park is 399 to center and 320 to right field

In each case, the team went to the Commish and said “hey, we’d like to put the fences closer than the rules allow” and he waived the requirement. Presumably, that’s what the Yankees will do to have their new digs built with dimensions that violate the rulebook requirement.

This raises an obvious question: if the Commissioner regularly waives the requirement, why is the requirement in the rules at all?

In hockey, they used to have some arenas that were not the same size (Boston, Buffalo, Chicago, I think), but when new arenas were built, they had to conform to the dimensions.  There were no exemptions.  I agree with Derek that allowing the commisioner discretion gives him too much power.  Since he’s now set different standards, they should be adjusted.  The 325 minimum should be changed to 315.  The 400 should be changed to 395.  I agree and accept that each field can have its own OF dimensions, but I disagree that they can get an exemption on the minimum (and maximum) distances.

Wednesday, February 28, 2007

Park Impact

Several years ago, I derided the sabermetricians’ adjustments for parks as much too simplistic.  It is an impossibility that Busch affects Coleman, McGee and Clark the same way.  This is even more clear if you think of Fenway and Coors.  MGL and I have had it out many times, with MGL’s position that “something is better than nothing”, and my position being “something is better than nothing, but still far from acceptable”.  I don’t mind seeing “park factors”, as I recently published a set on this blog.  The problem is simply applying these base adjustments equally to all players.  And worse, with no provision by the author of said adjustments, that a 5% increase for one player might be a 5% decrease for another player, in the same park.

The very resourceful John Walsh comes along with his look at specific players in Fenway Park, the most interesting of all parks for analysts, and most enjoyable of all parks for fans.  This is where the focus should be.

Thursday, February 15, 2007

Run Impact in Parks

Here you go…

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Thursday, January 25, 2007

Batted Balls at Fenway Park

A researcher can be quite content to spend half his time analyzing the effects of Fenway Park.  It has all the parameters that makes it interesting to study.  Plus, it’s a fantastic place to see a game.  A great marriage of analyzing cold hard numbers, and then appreciating baseball in all its glory.

But, we need help:

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Tuesday, January 23, 2007

Wind Patterns Affecting Stats

Yet another in the category of insightful, easy-to-digest, but heavily-researched articles.  Lots of great researchers out there who roll up their sleeves to bring great ideas to the masses.  This is what sabermetrics needs.

Thursday, December 28, 2006

Park Factors, 2004-2006

The park factors for the 2007 Bill James Handbook can be found on the errata page.  (Hat tip: DanAgonistes blog).

Monday, October 23, 2006

Weather-Park Factors

Good research by Chris Constancio.  One measure I like to use is (K+BB)PA, to show the percentage of plate appearances that end without contact being made.  In the cold times, that figure is .265, and in the hot times, that figure is .250.  So, batters take more (or pitchers are throwing in the corners more) when it’s cold.  Why would that be?  As Chris shows, there’s a huge gap in BABIP and HR between cold and hot.  If a batter thinks he’ll get on base more because of the walk, then he’ll sit and wait for it.  However, in low run environments, the walk has less value than in high ones.  So, it’s a huge balancing act to determine what the breakeven level is in the approach for the batter/hitter.

Thursday, July 27, 2006

Colorado Park Factor

Here is Dan Fox looking at park factors, for the minor league Colorado team.

The park configuration also plays a role.  I once did a(n unpublished) study on the park configuration, and…

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