Part I and II

Apparently, the debate is over and Barry Bonds is already guilty in the court of public opinion. The clearly unbiased Hank Aaron has already chimed in to help with Bonds' public lynching. Senator John McCain is grandstanding to pass legislation to protect America from the roid scare. No word from Jim Bunning, who still thinks he is playing professional baseball.

It seems that all that Bonds has to fear is the damage to his legacy. Baseball is probably not going to discipline him or Jason Giambi, who actually admitted to using steroids in the alleged grand jury testimony. And of course, the putative testimony was leaked because they didn’t have enough to go after the players. As for me, the only thing I know for sure after reading the leaked testimony was that Bonds has a deep fondness for the word "Dude".

Anyway, before this generation of ballplayers is dismissed as a bunch of overpriced, steroid-inflated lollygaggers ("we walked ten miles uphill to the ballpark in my day…both ways."), I started looking at the facts. And the facts are that the offensive surge started long before the steroid scare purportedly began. I showed yesterday, as well, that two rounds of expansion caused offenses to soar (in 1993 and '98).

Today, I'd like to look at the effect that new ballparks had. Now, this is just a quick method. I'm sure that a much more well-thought-out study could be made of the data. But I think even this quickie study is quite telling.

I took a look at the statistical impact that the new stadiums (since 1991) have had. I'd like to use the same stats as yesterday (home runs per plate appearance and slugging percentage). Here are the changes that were witnessed when the new stadiums cropped up.

First, these are the stadiums we will be examining:

Note that the Expos played just 20 games in Hiram Bithorn, but I decided to include anyway. Also, the M's moved to Safeco in mid-1999. I went with the first full season there (2000) and compared it to the last full season in Kingdome (1998).

Now here are the averages for all of the stadiums:

There's a wide dispersal in these data, but on average home runs increased by over ten percent after a team switched stadiums. Keep in mind that this includes a decrease in the tenuous inclusion of the San Juan Expos and that the Rangers new stadium did not have nearly the offensive numbers it has now.

The discerning mind will point out that the stadium increase could be result of the overall increase from year to year. However, if we subtract out the increases seen in the league the year that each stadium opened, we still see a marked increase:

So clearly the change in venue had some effect in the offensive numbers we've seen. I'll leave the study regarding steroids' effect to Jose Canseco.