# Comerica Hitters Park

The Tigers offense has been getting all kinds of well deserved pub. They’re averaging 6 runs a game. Little did we know that their pitcher’s paradise has played as a hitters haven so far in 2007.

Ever since Comerica Park opened in 2000 it has been cited as a pitcher’s park. While it did suppress run scoring a little, it’s always been possible for offenses to generate a decent batting average. Still, that spacious centerfield and deep left field have always suppressed homers. And when the left field fence was brought in it helped to even things out for the sluggers, but still it played to the pitcher’s advantage. Until this year.

Park Factors help to provide context to offensive events by comparing the offensive events in a home stadium to those on the road. I calculated the 2007 factors using the method described in the Bill James Handbook. In the case of homers, you add all the homers hit by the Tigers and their opponents in Comerica Park and dividing by the number of at-bats between the 2 teams. That number is then divided by the same calculation for when the Tigers are on the road and playing in their opponents parks and the result is multiplied by 100. A value of 110 would mean that it is 10% easier to achieve the feat at home, where a figure below 100 means that the park suppresses the event.

The table below shows the Comerica Park park factor for 2007, as well as the 2004-2006 seasons. The previous seasons were taken from the Bill James Handbook.

```		2007	04-06
Runs		110	 95
Hits		101	102
Doubles		102	 86
Triples		114	155
Homers		117	 86```

A couple things to note:

• Comerica is widely regarded as a great doubles park, and that is largely unfounded. Even this year it is barely above neutral.
• With batting average remaining pretty consistent, the increase in Comerica scoring has to be attributed to the increase in homers, and to a lesser extent doubles.
• Triples are down, but they are a rare enough occurrence and it is early enough in the season that 2 or 3 triples could really swing this. I have full confidence that Comerica Park and Triplesville will still produce plenty of 3 baggers.
• Related to triples, Curtis Granderson has single handedly impacted this metric with 10 of his 12 triples coming on the road.

I don’t mean to diminish the quality of the offense by attributing it to Comerica Park. The team is still hitting 289/349/472 on the road so the offense is just flat out good. We’re still barely more than a third of the way through the season, so it remains to be seen how this will play out. But for a park that has always played big in the past, it sure is playing small now.

1. June 12, 2007 at 10:31 am

It is possible that the decrease in power around MLB this year is causing things to shift a bit. Maybe fewer homeruns being hit in all parks means that a park like Comerica which is not a home run park has become a better offensive park relative to others. I’m a little skeptical as to whether there has been a real shift though. I think it’s more likely just a fluke based on small sample size. Park factors do tend to vary a lot from year to year.

Lee

2. Jason

June 12, 2007 at 11:55 am

I am sure if I went out an pitched every game at comerica, it would be the best “hitter’s park” in the majors.

3. Mike R

June 12, 2007 at 3:39 pm

Jason brings up an interesting point; does our pitching regressing from the numbers we put up last year have to do with it being a ‘hitters park’? I’m with Lee on this, it’s too small of a sample size right now, however, it’s interesting food for thought.

4. Mat

June 12, 2007 at 4:46 pm

I’m curious if this number holds up if you exclude the Tigers offense. Couldn’t our improved ’07 offense be the reason for Comerica looking so good this year? In other words, rather than the park making the offense look good, couldn’t the offense be making the park look good? I realize the metric takes both home and road rates into account, but it’s not unreasonable to assume the comfort zone that comes with home field familiarity makes the Tiger offense more productive in Detroit than they would otherwise be. Since the Tiger’s are making up about half the stat, it seem to have a high potential for bias.

The home field advantage would presumably also be true for our opponents, but if the Comerica offensive advantage stood up even for road teams, then I’d be more inclined to buy into the Comerica as hitter’s park theory, even with sample size considerations. From a quick glance at home vs. road ERA and avg, it might.

The doubles from 04-06 stat is pretty shocking. Interesting stats. Thanks.