From SABR member Alan Nathan at The Hardball Times on April 17, 2017:
Back in 2011, I wrote an article the primary focus of which was an attempt to postdict the effect of the humidor on home run production at Coors Field. The article was based in part on a piece of academic research I had done with my collaborators a few months earlier in which we did careful laboratory measurements of the effect of humidity on the weight and coefficient of restitution (COR, or the “bounciness”) of the baseball. The essential idea is that when a baseball is stored in a humid environment, it absorbs water, which has the dual effect of decreasing the COR and increasing the weight, both of which should result in a reduction in exit speed, all other things being equal.
It might be helpful to review the basic facts about Coors Field, which long has been viewed as a batter’s paradise and a pitcher’s nightmare. Because the air density in Denver is approximately 80 percent of that at sea level, fly balls carry farther and pitches have less movement, both of which contribute to an increase in a variety of offensive statistics, particularly home runs.
Now we fast forward to the 2017 season, where reports abound that the D-backs are reviving their plans to install a humidor, and it will probably happen within a month or so. D-backs CEO Derrick Hall is quoted as saying regarding the humidor, “Again, I don’t know if it’s going to make a difference. It hasn’t made a huge difference at Coors Field, I don’t think.”
Read the full article here: http://www.hardballtimes.com/a-humidor-at-chase-field-whats-up-with-that/
Originally published: April 17, 2017. Last Updated: April 17, 2017.