Including an exhibition set against the Cubs, there’s only been a handful of games played at the new Yankee Stadium, to date. Yet, it seems like baseballs are flying out of the new ballpark in the Bronx. Wondering about this, on April 18th, as the Cleveland Indians were pounding the Yankees in the House that Stein Built, I dashed off the following question to Greg Rybarczyk who runs the website Hit Tracker and who knows a thing or two about homeruns, park factors, and such:
The homeruns have been flying out of the new Yankee Stadium, especially to right field, albeit over just a few games. I was wondering if you’ve done any analysis on this, or had some thoughts on it, that you would be willing to share?
Much to my pleasure, Greg Rybarczyk responded with the following:
The possible lively ball is something I’ve been tracking by looking at average weather-neutralized home run distances. Let me explain that before I go on. I have tracked all home runs for the past three seasons, and for each, I have noted the altitude and weather that each was hit in. After figuring out how far a given home run actually flew (I call this “true distance”), my Hit Tracker program allows me to adjust the altitude and weather to a standard set of conditions and see how far the ball would have gone. I call that “standard distance”. The idea is that a home run hit in Coors Field, or a home run hit on a 100 degree day in Arlington, Texas, or a home run hit into a strong wind at Wrigley Field, can all be compared by taking out those atmospheric influences and comparing their standard distances.
So, very early this season (actually on the second full day of games), I had already noticed that balls were seemingly flying farther than they usually do, so I checked my numbers, and noticed that the standard distances of all the home runs around MLB were a lot longer than those hit in 2008. Since then, I’ve continues tracking this, and what was little more than a feeling and some numbers off a very small sample size have become a lot more compelling: the first 350 home runs this year are flying, on average, about 6 feet farther than last year. The likellihood that such a difference could come about by chance is exceedingly low, less than 0.0031% the last time I ran the stats on that. I’ve tried to come up with some other possible ways that league-wide homers could be flying so much farther, given that the weather is already factored out, and the ball is the most likely explanation.
Now, if these numbers wre happening in isolation, I’d be more cautious about theorizing on this, but we are at 2.26 home runs per game (a high rate considering it’s April, the coldest month of the year on average), and on the observation side, my own eyes (which have watched every one of the more than 15,000 home runs hit in the last 3 + seasons) tell me the ball is carrying farther, and lots of announcers (who also see a lot of fly balls hit) are saying the same thing. (You might also want to check out this thread from the “Book Blog” regarding the possible lively ball.)
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Possibly because they think increased offense may help offset any threat of an attendance decrease from the economic situation.
Perhaps I'm spending time with an anomalous group of baseball fans, but I don't know people who talk about the PED issue in baseball. From what I see and hear, the PED issue is one only harped on by the media – and I cringe at making such a generalization like that – but I never hear this topic amongst friends who are fans unless they are discussing what they think will happen to a player's Hall of Fame candidacy (Clemens, Bonds, Alex Rodriguez, etc.).
ok, let's wait a month or two.
I hope the homers keep flying out, league-wide. It'll be fun around here.
Now, there would seem to be questions about how surely we can know the typical distribution of homers and typical variance, and there would further be the question of whether a variety of weather and other fluke factors could be the cause, but Rybarczyk is claiming quite explicitly that the sample is more than large enough to make confident judgments.
Just the opposite...since baseball is now testing and offense is as high as ever. Then...there never was a "Steroid Era" when it came to the numbers.
Shrewd if you ask me.
Of course...if you ask me. Steroids have had very little to do with the "Live Ball Era II" anyway.
Exactly. Exactly what I was thinking last night when reading the Book Blog thread linked in the Lounge.
1) Offense was high a few years ago
2) A number of people took steroids/HGH/whateva a few years ago
3) Some of those were pitchers
4) Some of those were hitters
5) It evened out
6) That means the numbers don't need to be adjusted
7) Which means the fans weren't cheated
8) Offense is high again this year
9) Which proves everything above
That's a storyline that can be sold. It's dumb as a coondog sniffing a lawn gnome's butt, but you could sell it.
One weird thing is that, if you look at the AL teams below league-average in pitching, in addition to the usual suspects (TEX, BAL, CLE), you've got some teams that, at least on paper, have good pitching (MIN, BOS, NYY), and the Angels and Rays are barely above league-average. Seattle and Kansas City actually have staff ERAs below 3.
Looking at it, it looks like there are four pitching staffs in the AL that are getting crushed - The Rangers, Indians, Orioles, and Yankees. In the NL, it looks like the Phillies (wow, all the Phillies starters are getting hammered early on) and the Nationals are the big offenders.
So far, just glancing at the numbers, it looks like we're getting wildly varying scoring environments in different parks, with the aggregate affect being an increase in scoring. I don't know what to make of it.
And yet the Yankees have three starters with ERAs of 2.51 (Pettitte), 2.70 (Burnett) and 3.57 (Sabathia), which makes their overall 6.84 ERA seem positively bizarre.
Well, it need hardly be mentioned, but...
Yankees road ERA - 4.91
Yankees home ERA - 12.33
Yankees' hitters are OPS'ing about 150 points higher at home than on the road so far, as well.
Granted I haven't seen his data either, but I'm very skeptical as well.
Is six feet really that big of a difference over two weeks? Really?
If they could figure out what was causing it, they could do build something to adjust the wind patterns.
The data tells you whether it is enough to tell, and gives you a % likelihood. The data I ran a few days ago looked like this:
Two-Sample T-Test and CI: 2009, 2008
Two-sample T for 2009 vs 2008
N Mean StDev SE Mean
2009 199 399.8 27.8 2.0
2008 4820 391.3 25.4 0.37
Difference = mu (2009) - mu (2008)
Estimate for difference: 8.49
95% CI for difference: (4.54, 12.45)
T-Test of difference = 0 (vs not =)
: T-Value = 4.23 P-Value = 0.000 DF = 211
The translation of this output is this:
the average home run distance (standard distance, i.e. weather-neutralized) for 2009 season-to-date was 399.8 feet, while for the entirety of 2008, it was 391.3 feet, for a difference of 8.49 feet
It is 95% likely that the actual difference between the two seasons is between 4.54 feet and 12.45 feet.
The likelihood that the data for 2009 and the data for 2008 share the identical underlying distribution is 0.000 (to three digits) - and actually, I used another program to check, and the number is 0.0000341. Another way of saying this is that there is a 99.99659% chance that 2009 homers are truly flying farther than 2008 homers.
Now, let me just say that at the time I ran these numbers, there hadn't been any games at the New Yankee Stadium, and the four games since then have knocked the 2009 distance nmbers down a great deal - but that's what happens when you have five home runs in one game (the 22-4 blowout) with standard distances below 352 feet. If the theory says that the ball is adding a handful of feet to fly balls, then you not only get longer home runs to increase your average distance, but you get more "barely homers" that reduce your average distance.
Which all means that the idea that the ball may be lively can only be a theory, unless/until someone tests the balls to be sure. But, I still think that it is likely that the balls this year are more lively. How much, I can't really say. And why, I can't say either, but let me go on teh record as saying I can't imagine that anyone would do this intentionally. It's plenty hard enough to keep a manufacturing process stable, we don't need to introduce any conspiracy theories if/when we find that the process has shifted slightly..
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