April 8, 2020

Ballparks Database Updated!

April 30, 2012 by · 2 Comments 

The Seamheads.com Ballparks Database has now been updated with 2011 data plus the latest and greatest corrections.

As a reminder, we provide two sets of calculations: 1-year factors and 3-year factors.

The 1-year factors are observed factors, based on only the season in question.  While we do use an other parks corrector as described in the detail documentation, these are essentially the factors that were observed for that particular year, so a 120 doubles factor for LH batters in Fenway Park means that left-handed batters hit 20% more doubles at Fenway than LH batters for those same teams’ batters hit in games away from Fenway.

The 3-year factors are attempts at calculating “truer” factors.  There are many, many ways we could have constructed our formula, and it’s difficult to determine what the “best” way is, but we believe our way is at least a good and defensible way.  Our basic formula is to use the 1-year factors for the season in question, the season immediately preceding, the season immediately following, and then the park’s long-term historical factor, all weighted equally.  As some parks have rather long histories, while other may have life for only a few seasons, this is not a perfect method, but we believe it retains a basic simplicity while providing for a high degree of accuracy in estimating a park’s impact on offensive events.

We welcome any feedback on any of the data or suggestions for improvement, so try it out and enjoy!



2 Responses to “Ballparks Database Updated!”
  1. Rod says:

    I don’t believe you have some of the dimensions or outfield wall height correct for Comiskey I. During his second ownership stint with the White Sox from 1976 through 1980, Bill Veeck removed a termporary center field fence that was about 400 feet from home plate, which left a brick wall that stood at least 15 feet high and was 445 feet to straight away center field. A temporary fence was re-installed in 1981 when Jerry Reinsdorf bought the team. I also recall that in 1983, the Sox moved home plate about six or seven feet out toward center field, thereby shortening all the dimensions of the park.

  2. Rod – Thanks for the input.

    I thiink we do show those changes,except for the wall height? We have the CF fence going from 400 to 440 ft in 1976 then 445 in 1977 when the temporary fence was moved. I’m guessing the marked distance in 1976 was just wrong, then corrected in 1977. We have the temporary fence installed and the distance for CF back to 409 in 1981. In 1983, the plate was moved, but according to Green Cathedrals it only impacted the LF and RF foul line distances.

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