Was Watching: Is The New Yankee Stadium A Homer Haven?

I demand those 264,865 “Steroid Era” articles be retracted!

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.)