5/23/2018

A Handy Guide to the Future

Note: this was written during our 1930 season, so when the phrase “this season” appears, it’s 1930.

Since some folks like to construct their teams based on their ballparks (at least to the extent that this league makes that possible), it might be helpful to know when and how these ballparks change.

In my opinion, the easiest thing to get confused about when dealing with park factors is this: park factors sometimes change even when the park doesn’t. Park factors are based on statistics, but they are also based on how the park compares to the other parks in its league. Therefore a park’s factors will change every time one or more park in the league changes. What has changed is not how much that park affects batting average or home runs, but how its effects compare to the league as a whole.

Keep in mind that we don’t have splits data for any of the parks, so unless their configurations are particularly asymmetrical, equal L/R splits will be assumed.

HOLLYWOOD/SAN DIEGO

From now until 1935 the Stars play at Wrigley Field (see Los Angeles comment).

When they move to San Diego to become the Padres in 1936, they play at Lane Field. From 1936-1944 Lane is a very poor home run park, decreasing home runs by around 25%. After 1945 they move the fences in and it becomes a good home run park. For most years after 1945 it increases homers by about 12%. Lane does not favor lefties or righties and has less than a one percent affect on batting average.

LOS ANGELES

The Angels play at Wrigley Field, which keeps its original dimensions for the duration. Neutral for L/R splits; anything but neutral in its effect on home runs. Wrigley increases home runs by anywhere from 50% to 100%. Usually right in the middle, at around 75%. These are absolutely absurd and hard-to-believe amounts, but the statistics bear them out. This is as much a comment on how tough it is to homer in most of the other parks as it is a comment on how easy it is to homer at Wrigley. Wrigley increases batting average by about one percent most years.

MISSION/HOLLYWOOD

The Bells play their final season at Recreation Park this year, then move to Seals Stadium (see San Francisco comment).

The Bells become the new Hollywood Stars in 1938. They play at Wrigley (see Los Angeles comment) for a year, then move to their permanent home at Gilmore Field in 1939. Gilmore is a slight hitters’ park, inflating batting average by no more than one percent. Because a number of the other parks in the league are revamped at different times in the 40’s, in some years the number of home runs hit at Gilmore is above the league average, and in others it is slightly below the league average. Gilmore is neutral for L/R splits.

OAKLAND

The Oaks play at Oaks Park, by far the best pitchers’ park in the league until the fences are adjusted in 1946. From now through ’45, Oaks reduces batting average by around 5% (which is a lot), and home runs by around 50%. It’s slightly better for LHB in batting average, and slightly better for RHB in home runs, but it’s a terrible park for hitters both ways.

That all changes in 1946, when they build bleachers and scoot the fences in and it becomes the second best hitters’ park in the league. From that point on Oaks increases batting average by about one percent and homers by about 20%, slightly more for LHB.

PORTLAND

The Beavers play at venerable old Vaughn Street Park until we get to 1956, if we ever do. It’s a hitters’ park, especially for home runs, which depending on the other parks in the league through the years increases homers by 6% to 32%. It’s a good home run park from both sides of the plate, better for lefties.

For batting average Vaughn Street is usually a hair above average for RHB and a hair below for LHB. We’re talking around 1% in either case.

SACRAMENTO

The Solons’ park changes its name a few times, but it is always a perfectly symmetrical park with average distances to the foul poles and a good long train ride to the center field wall. For batting average it skews towards pitchers by one or two percent; for home runs, a lot more. It reduces home runs by anywhere from about 10% to 25%.

SAN FRANCISCO

One more season at homer-friendly Recreation Park and then it’s on to Seals Stadium, where home runs are forbidden by law. Seals is friendly to singles hitters, though, increasing batting average by around 3% until its 1943 reconfiguration, and about 1% after that. Pre-1943 it reduces home runs by an astonishing 60-70%. They add a small bleacher section in right field in 1943, which increases home runs to the point where it is only the second-worst home run park in the league for a few years. Then the Oaks add some bleachers, and Seals is back to being the league’s toughest park to homer in. For most of the 1943- period it reduces home runs by around 30-40%. Before 1943 it is slightly easier for a right-handed hitter to hit a home run there; after the bleacher section arrives it becomes easier for a left-handed hitter.

SEATTLE

The Rainiers will play the rest of this season and all of 1931 at Dugdale Park, a pitchers’ park that reduces batting average by around 2% and home runs by around 20%-30%. Then in 1932 it’s the dust-and-mud festival at Civic “Field”. The PCL Parks book by Larry Zuckerman only has 30 games worth of data for Civic; it’s the one thing in the book I don’t trust. Not because I think the data is inaccurate, but because 30 games is an eentsy sample size for park factors. Taken at face value the data suggests Civic should almost triple home run output. I think it’s pretty unlikely that would have held up over time, and we’re going to be stuck playing games at this place for six seasons. So I’m going to give Civic a Wrigley-Field-level home run factor, which is plenty ridiculous. Civic will reduce batting average by about 1% while increasing homers by about 70%-95%.

And then, thank God, we’ll be rid of it, as the Rainiers move into Sick’s Stadium in 1938. Sick’s was built on the same plot of land where Dugdale had stood, and almost perfectly mimics the former park’s effects. Sick’s will reduce batting average by one or two percent and home runs by around 20-35%.

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