Written by Greg Fertel
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14 May 2008
The Waterfront Park in Trenton has always fascinated me. For as long as I can remember, hitters have gotten off to abysmal starts in that ballpark. Last year, the slow starters were Juan Miranda, Brett Gardner, and especially Justin Christian, not to mention Cody Ehlers and P.J. Pilittere. In 2006, you had slow starts from Shelley Duncan and Justin Christian before they started hitting again. The team has always picked it up come summer.
Minor league park factors are very hard to figure out, and have always been a topic of interest for me. Long-time readers will recall that my first series of posts on this blog were about minor league park factors. The reason is that they are so elusive is that you have both a league factor and a park factor, and they vary year to year. Some years, the Eastern League might have better players than the Texas League. In addition, minor league ballparks tend to be a little more funky than major league parks.
A lot of things are at work when we talk about ballpark effects on the baseball. The distance and angles of the fences can be important, but much more is going on. Humidity, air temperature, wind speed, wind direction, weather, altitude, the batter's eye, noise level, grounds crew, and pre-game facilities such as batting cages all contribute. Trying to identify causes are difficult, but we can measure effect. Effect is measured by tracking the home/road splits of batters. The problem with this method? It doesn't pick up league effects.
Trenton plays out as a slight pitchers park overall.
The park factor from 2007 was 0.96 runs, meaning that pitchers have a 4% advantage over hitters (2% in reality, since we're only counting home games).
First Inning makes an attempt to track league factors, and the Eastern League plays out as a very slight pitchers league, cutting singles, doubles, triples, and home runs by 1-4 percentage points each.
Now, we can try to place some anecdotal evidence into these numbers to figure out what is going on. A reader in the comments section of the 5/13 Recap pointed out that the wind blows in at night, knocking down home runs. To add my own observation, that wind tends to be very cold at night. It comes in off the water and is prone to pretty strong bursts. Once the water warms up a little bit, the bursts become a steady breeze and its not so damn cold.
You can take a look at First Inning's 2008 park factors at the link above. They are essentially meaningless numbers given the small sample size. Those factors have Akron, a traditionally strong pitcher's park, as an extreme hitting environment. Baseball Think Factory's 3-year factors seem to conform much more to expectations. It is 16% harder to hit a home run in Waterfront Park than it is in a neutral Eastern League ballpark. All of the other factors are essentially neutral. Austin Jackson's power numbers may suffer a bit, but he still should be hitting something out of the park. Mentally, I'd add 40 points of slugging and a few points of OBP/BA to his line.
By the way, take a look at the Met's affiliate Tri-City on that list. It is 50% easier to hit a home run there than in a neutral park. Wow.
