Wednesday, April 22, 2009

Maybe it's not the new stadium...

From here:
The distance of the home runs being hit this year (the true distance, i.e where they actually land, as well as the standard distance, which factors out weather and altitude) is significantly higher than last year, with the average standard distance being 8.5 feet longer this year than last. 
The p-value actually works out to 0.0000341, which is a very strong indicator that something is making 2009 home runs fly farther than 2008 home runs, in isolation of the weather, and to me that implicates the ball. 
Ball speed off the bat is also up. And, as you would expect, so are home run totals. I will say that, as others have observed, the ball has appeared to me to be exploding off bats this year. I've been amazed at some of the balls that have gotten out at Yankee Stadium. Maybe my observations are being influenced by other people's commentary, but I thought I'd throw that out there. Apparently, this phenomenon is going on everywhere.

One of the most underreported stories of the so-called "Steroid Era" is that the spike in offense was not the gradual increase that one would expect if steroids were slowly permeating the game. It was a very sharp spike in the early 1990's (starting in 1993, if my memory serves; could be 1994). If we are to accept that steroids caused the surge in output, we must accept that hitters all started using simultaneously. This is highly unlikely. The much more likely explanation is that something changed about the playing environment, something universal.

The most likely culprit is the ball, and indeed there is empirical evidence demonstrating that the core of the ball changed and changed enough to cause a spike in home runs. It appears that something fishy is going on again this year. I'll be very interested to see how this plays out.

UPDATE: Apparently Brian Cashman reads the same blogs I do. ESPN reports that "Cashman also said home runs are traveling about eight feet farther so far this year compared to last season." Furthermore, Cashman is quoted as saying, "The ball is going farther in every park, not just ours." Fascinating.

**EDIT** Fixed typo noted in comments.


rklllama said...

I know we're just two weeks into the season, but is eight and a half feet enough to make Jeter's doubles homers?

John Lynch said...

It could be. It could also turn long fly outs into home runs. Eight and a half feet is enormous. Keep in mind that this isn't saying that any particular player has been helped, just that the ball is traveling farther overall.

D.Cous. said...

1. You've got a typo here: "to be exploding of bats this year."

2. I have yet to see a single game this year. Either this must change, or I must stop reading your blog about baseball, because doing so just reminds me that I haven't gotten to watch any baseball.

3. Couldn't a ball travel ~8' further just by not being caught by someone, and instead hitting the empty stands? Perhaps it's because nobody's in the stands this year. Alternately, could the stands in the new stadium be deeper (with a lower slope)? I think that could have an effect. (If both of these questions seem silly, see #2).

4. Does anyone keep track of where the baseballs used in MLB come from? I would suspect them to be highly regulated by the league, and possibly even all manufactured by the same company. Have you nowhere to go to even partially confirm your suspicion? I heard somewhere that most baseballs are made in the D.R.

5. If the ball is different, there are a couple of possible explanations, one being that MLB knows about it, and is trying to sexy up the game for television. This is probably not the most likely explanation, but it is an explanation.

John Lynch said...


3. The measurements be used here are independent of factors like whether or not the ball is caught by anyone or whether or not it hits anything. See for details on the process.

4. MLB does regulate the balls, but their idea of what constitutes regulation is very, very broad. Those who have studied the issue have deemed the regulation to be essentially a joke. It's very possible that the eight and a half foot difference could manifest between balls that both technically meet MLB's specification.