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Back in April–you remember April, don’t you?–you couldn’t click your
mouse without reading about how baseball had simply become slow-pitch
softball with warmer, more expensive beer. Scoring was up, ERAs were up,
home runs were up and interns were being run ragged chasing the latest,
greatest freak stat to prove that the game had gone completely nuts. Surely
something had to be done!

The following e-mail found its way to my box last week:

Is it just my imagination, or has the home-run onslaught run out of steam?
This is August, when the sluggers are supposed to get cranked up, but it
appears to me that the HR production is off from what it was in the spring.

Rich Wittish

Rich’s question helped, because I thought maybe it was just me. It
certainly did seem that there had been a dropoff in scoring and in home
runs as the summer progressed, but I couldn’t quantify it. His e-mail
prompted me to do so.

(All numbers in this article are through August 12.)

First off, the most basic question: are home runs still up over last year?
On a per-at-bat basis, yes, they are:

         AB/HR
2000      28.1
1999      30.2

That’s a 7% increase in the home-run rate through about 3/4 of the season,
a significant jump.

Now, some of you will point out that MLB traded the Astrodome for Enron
Field this season, and that alone should account for a big jump in home
runs. It has. There has been a 124% increase in the home run rate in games
played in Houston.

But two more new parks came online, Pacific Bell Park in San Francisco and
Comerica Park in Detroit. And in those parks, the home-run rate has
declined as compared to their predecessors.

                       AB/HR
                   1999     2000   Change

Detroit 23.5 39.3 -67% San Francisco 29.9 32.7 -9% Houston 46.6 20.8 +124%

Total 30.8 28.9 +6.5%

The rate of increase in home runs in the three new parks has actually
lagged slightly behind the rate for all other parks. In the 26 parks that
saw complete seasons in 1999 and 2000, the home-run rate is up about 9%:

         AB/HR
2000      27.9
1999      30.4

(Adding the data for Seattle, which had two parks in 1999, doesn’t change
the conclusion, just the numbers. Using a 27-park sample yields an increase
of 8%.)

So the jump in home runs is real, and not a product of Enron Field.

But what about Rich’s original question? Has the home-run barrage lost some
steam? Here is the MLB home-run rate by month for this season:

2000        AB/HR

April 26.8 May 26.2 June 27.9 July 29.8 August 33.5

So that batch of balata balls showed up, what, around July 10?

Well, maybe. Warm, dry weather is supposed to be better for the long ball,
so this is a highly unusual pattern. Let’s take a look at the progression
in 1999:

1999        AB/HR

April 30.9 May 29.2 June 30.6 July 29.6 August 31.5

No real pattern, but that same spike in August. Let’s look at the two
charts together to get an idea of the change:

             1999       2000
            AB/HR      AB/HR     Change

April 30.9 26.8 +15% May 29.2 26.2 +12% June 30.6 27.9 +9% July 29.6 29.8 0% August 31.5 33.5 -7%

Homers were up 12% in the first three months of the season over a similar
period in 1999. Since then, they’re down about 1%.

So yes, Rich, there has definitely been a slowdown in the rate of home runs
this summer.

How about offense in general? Is this still a historic year for run-scoring?

       1999     2000
        R/G      R/G   Change
AL     5.17     5.31      +3%
NL     5.00     5.05      +1%

Offense is up, but not by as much as you might think. Like the home-run
increase, it’s mostly an early-season phenomenon, one that has leveled off
as the season has worn on.

                R/G
March/April    5.37
May            5.26
June           5.21
July           5.10
August         4.99

There are some other points that indicate that home runs have leveled off.
No one is going to hit 60 home runs this year. There’s a small chance that
no one will hit 50 home runs,.which would make this the first full season
since 1993 that no one has has topped that number.

There are still six weeks of baseball left. More than enough time for the
early-season trends to reestablish themselves and make this look like a
homer-happy season. I don’t have any great explanations for the falloff,
other than the oh-so-satisfying "small sample size".

But at this point, it seems like the baseball we saw early this season may
have been a bit of a fluke. We’re still in a hitters’ era, but maybe
there’s room for some pitching after all.

Joe Sheehan can be reached at jsheehan@baseballprospectus.com.

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