The Humidor of Chase Field
A humidor is a humidity-controlled storage area, usually used for storing cigars. So how could one possibly affect the outcome of hitting home runs? At Chase Field in Arizona, the Diamondbacks have installed a humidor within their ballpark in which the baseballs are stored. Coming off of seasons in which the Diamondback organization witnessed 221 home runs in 2016 and 215 home runs in 2017, they wanted to make a change to try and benefit their pitchers. The humidor is supposed to control the moisture level in a baseball and as a result, home run totals should decline.
To test this, the results of all home runs hit at Chase Field from 2015 through this season were taken into account. 2015 was used as the starting point because that’s when Statcast introduced exit velocities and launch angles.
The minimum exit velocity for a home run hit in the Statcast era at Chase Field was 93mph in 2017. For the other four years it has been 94mph. Also included in the table are maximum exit velocities, minimum launch angles, and maximum launch angles. From these numbers, fly balls hit during each year under those metrics can be filtered in. By then factoring in home run totals from each year, a home run percentage per fly ball rate can be identified from the Statcast metrics.
The results of the findings are shown in the bar chart above. Chase Field home runs were sky rocketing up until this season. The data shown above proves that the humidor installed by the Arizona Diamondbacks has helped alter those numbers, keeping the ball in the park far more often this season.