The Diamond Discrptancy… Looking at Major League Baseball through its Stadiums.

Because of a variety of environmental factors, including the lack of a uniform field size, the hitter and pitcher-friendliness of certain MLB ballparks can have distinct outcomes in terms of how teams perform in said stadiums.

Data courtesy of http://www.baseballref

The positive correlation between Ballpark Index and ERA+ shows how those looking to get a competitive advantage in MLB can used advanced analytics to reveal hidden patterns and outliers for certain playing fields. In what is typically a completely neutral environment for most sports, baseball teams who look between the lines can see the difference that a playing environment like Coors Field and T-Mobile Park can have (with a ERA+ differential of 40 and a BPI differential of 20) between the two fields in relation to an average MLB ballpark).

Notable Insights:

  • Coors Field, home of the Colorado Rockies, is located over a mile above sea-level, causing baseballs to travel an average of 25% further when put in the air. The Rockies compensated for this with built in stadium humidifiers, as well as the largest field dimensions of any one team.
  • T-Mobile Park, home of the Seattle Mariners, typically plays with an open roof which can create a very pitcher-friendly environment when flyballs are subjected to turbulent Seattle wind.
  • Aside from 3 teams with R’s inexplicably being the 3 most hitter friendly environments, Great American Ballpark, home of the Cincinatti Reds, has had the most Homr Runs of any stadium since it opened in 2003. Opening much earlier in 1912, Fenway Park is known for its extremely unorthodox dimensions. Home of the Boston Red Sox, the stadium has the deepest centerfield (420), the shallowest right field (302), and a 37 foot tall wall in left field (known affectionately as the Green Monster.)

This portion of the chart will allow the user to click a drop down menu and find the BPI to RA/G for each of the last 10 years, allowing users to track the volatility of which teams sustain status as hitter/pitcher friendly.

Select Year:

  • 2021
  • 2020
  • 2019
  • 2018
  • 2017
  • 2016
  • 2015
  • 2014
  • 2013
Data courtesy of baseballsavant and baseball-reference.