With the 2004 season in the books the Brewers have now played four seasons in Miller Park. When Miller Park opened in 2001 it was touted as a great place for hitters. That year, 222 home runs were hit at Miller Park compared to 184 in Brewer road games. But, even with the extra home runs, Miller Park barely inflated run production with 774 runs scored in Brewer home games compared to 767 on the road. In fact, according to www.baseball-reference.com Miller Park has played almost completely park neutral last four years as far as scoring runs.
|Miller Park's Runs Scored Factor|
A park factor of 100 is a neutral park. A number above 100 is favorable to hitters and below 100 favorable to pitchers. These park factors are calculated using runs scored and runs allowed in home and road games and then adjusted for things like extra plate appearances at home or on the road. A full explanation of this method can be found here
If Miller Park is such a great place to hit homers why is it playing park neutral for runs? Obviously, Miller Park must be suppressing something else that is balancing out the extra home runs being hit. This study will try to determine how Miller Park is is affecting other aspects of offense to counteract all the home runs being hit. Once this is known, we can determine which types of hitters and pitchers will perform the best in this stadium.
For this study I used home and road splits for the following statistics: singles, doubles, triples, home runs, walks, and strikeouts. When possible three year averages were used. For 2001 and 2004 two year averages were calculated. For example, to determine Miller Park's park factor for home runs in 2002, divide home runs per plate appearance at Miller Park from 2001 to 2003 by the home runs per plate appearance in road games multiplied by 100. If the percentage was more than 100 then Miller Park inflated the number of home runs hit for that year. The accuracy of this method is reduced by the unbalanced schedule and interleague play but it gives a good picture and is relatively easy to calculate.
The figure below shows Miller Park's park factor for each statistic. This figure isn't intended to show changes in how the park plays from year to year but which of these statistics have stabilized in the four years allowing us to draw conclusions.
Let's examine each of our statistics individually starting with home runs.
Miller park has had the largest effect on home runs in its four year stint. Home runs have been inflated by over 10% in that time. This is a significant amount as it can turn a 40 homer season into a 44 home run year. Players with extra pop are definitely going to be helped playing half their games in Miller Park.
Triples are all over the map, being suppressed 10% in 2001 to being inflated 7% in 2004. Triples are a rare occurrence so a few extra triples in a year can make a park look like a triples haven. More years will be needed to determine what effect Miller Park really has on triples.
Miller Park has also been kind to doubles hitters, increasing the number of doubles by about 4%. It is very strange to see a park being generous to both doubles and home runs. Normally, if the park has a short fence the number of home runs go up and the number of doubles go down. As the fences get pushed back doubles inflate and home runs are suppressed. Because Miller Park isn't turning home runs into doubles this increase must be coming from somewhere else.
Miller Park also has had a very large effect on singles. Singles have been suppressed by 6%. Because singles are very abundant, small effects can have a large impact on the number of runs scored. Some of these singles are probably being turned into doubles, but most of them must be being turned into outs to counteract the scoring increase from the doubles and home runs.
Walks and strikeouts are normally correlated to the amount of foul territory in the park. The less foul ground the more extra chances to walk or strikeout. Miller Park seems to favor strikeouts over walks suggesting that hitter's may be having a hard time picking up the ball. It's possible that this is a result from the shadows that players have complained about especially in day games. The park factor for walks has increased each of the four years though so this will be something to watch in the upcoming years.
Adding it all up, while Miller Park has played basically run neutral, it has a large effect of certain aspects of the game. Hitters with a high slugging percentage will be greatly helped by Miller Park but singles hitters who strike out too much will be punished. A power hitter like Carlos Lee who doesn't strike out that much might find Miller Park a very cozy place to play. On the other hand, Miller Park could have really been effecting how successful players like Scott Podsendik are. As far as pitchers go, power pitchers that can keep the ball in the yard will benefit from Miller Park. Pitchers like Ben Sheets can be even more dominant, but someone like Rick Helling probably will flop.