from Amazon
Sunday, June 01, 2008
Why is the HFA so high this year?
I did not realize it was until I read this article on ESPN.com. In it, Buster Olney takes on the question as to why the home teams are winning at a .577 clip so far this year (as of May 29, according to Olney).
In the article, Olney says, according to several GM’s, players, managers and scouts, it might because of the “influx of young players” who are more familiar with their home environments, or perhaps even party on the road, more so than the average player I guess.
As I said, I hadn’t even noticed that home teams are winning at such a high rate so far this year, and normally I wouldn’t think anything of it anyway. But given the sample size, the difference between this year and what is typical (around 53-54%) is greater than 2 SD, enough to raise an eyebrow or two. Plus, there are a lot of weird things going on in baseball so far this year (well, at least one weird thing, which is the low run scoring and especially HR rate in the AL).
Anyway, the “young players” explanation seems a little silly to me on its face. I mean how many extra young players would it take to make such a difference?
Not one to accept anything at face value, especially that which “scouts, managers, GM’s, and players” posit, I looked at the average age and distribution of ages of pitchers and batters so far this year as compared to last year at the same time (thru May 29). Each age is prorated by the number of PA or TBF. The distribution of ages is percentage of total PA or TBF. Here is what I found:
2007 NL Batters
Av age: 29.8 < 25 .11 25-30: .42 30-35: .31 >35: .16
2008 NL Batters
Av age: 29.3 < 25 .10 25-30: .47 30-35: .32 >35: .11
2007 NL Pitchers
Av age: 29.6 < 25 .11 25-30: .48 30-35: .28 >35: .13
2008 NL Pitchers
Av age: 29.4 < 25 .13 25-30: .40 30-35: .35 >35: .12
2007 AL Batters
Av age: 30.1 < 25 .10 25-30: .33 30-35: .44 >35: .14
2008 AL Batters
Av age: 30.0 < 25 .10 25-30: .38 30-35: .38 >35: .14
2007 AL Pitchers
Av age: 29.0 < 25 .14 25-30: .44 30-35: .30 >35: .12
2008 AL Pitchers
Av age: 28.9 < 25 .12 25-30: .52 30-35: .22 >35: .13
The average age among NL batters is .5 years less than last year and among NL pitchers it is .1 less. In the AL, it is .1 for the batters and .1 for the pitchers.
However, there is no noticeable difference in the number of under-25 players. In the NL, there are 1% fewer under-25 batters and 2% more under-25 pitchers.
In the AL, the number of under-25 batters is the same as last year, and for pitchers, there are 2% fewer under-25’s.
Even if it were true that “young players” do better at home than on the road, relative to the average player – and that is a shaky theory at best, IMO – I don’t know where all the GM’s. players, managers, and scouts got the idea that there are more “young players” in baseball this year than in past years, or at least as compared to last year. There aren’t, even though the average age in baseball is slightly less than last year. Do they just say the first thing that comes to their minds? I don’t know.
Here is a nice conspiracy theory to explain the higher HFA this year: If it is true that teams are now allowed to keep their baseballs in climate controlled environments, what is to prevent them from taking out the livelier balls when they are batting or when they are behind in the game? I have mentioned that several times over the years with regards to the Rockies and the humidor. It seems to me that if you allow each team to “doctor” the baseballs, even if that means getting them back to their “original” condition, you are just asking some teams to cheat. People will cheat when given the chance.
Just a theory. Hey, I think it is a heck of a lot better than the “younger players” theory! At least I am not making up facts.