Should Arizona's Humidor Affect Your Fantasy Baseball Rankings For Diamondbacks Players?
For years, Chase Field has been one of baseball's friendliest havens for sluggers. Last year, the ballpark played as the fourth-easiest in baseball in which to hit a homer, according to ESPN park factors. The year before that, it was second, and in 2014, it was the seventh-easiest park in which to blast a dinger.
Now, team officials say they will begin storing baseballs inside a humidor at the stadium which will be a climate-controlled, 50% humidity, 70-degree environment, in an effort to combat the fact that Chase exists 1,059 feet above sea level (Coors Field in Colorado is at 5,211 feet) and is located in a part of the country that averages about 20% humidity.
It's easier to hit homers in the desert because the air is thinner and the climate is warmer. But how much will a humidor actually depress home runs?
It Worked At Coors
Only one other ballpark in the majors stores their baseballs in a humidor in the Colorado Rockies. While the humidor hasn't stopped Coors from continuing to be one of the easiest in which to hit a homer (fifth-easiest last year), recent studies indicate that the humidor has done its job.
"The humidor didn't matter in Coors; why will it matter in Chase?"
Oh, yes, good point, except let me add, the humidor made a huge difference in Coors!
(Re-post with the corrected chart) pic.twitter.com/iR3Q0Z0vgT
â€” Derek Carty (@DerekCarty) February 1, 2018
Players still hit dingers out of Coors Field with regularity, but the humidor has reduced the rate at which those homers fly out of that stadium while at the same time reducing offense overall. Alan Nathan, a physics professor at the University of Illinois, noted in a 2017 FanGraphs piece that the decline in home runs was immediate beginning in 2002 when the humidor went into effect. Nathan wrote:
"For the first seven seasons at Coors, there were 3.20 home runs per game compared to 1.93 per Rockies away game. However, starting in 2002 the Colorado Rockies began to store their baseballs in a humidor at a constant 50 percent relative humidity and 700F, as opposed to the more typical 30 percent humidity in Denver. During the period from 2002-2010, the Coors ratio decreased to 2.39, a reduction of 25 percent, while the away game ratio stayed essentially constant at 1.86."
Of course, that 25% reduction in homers at Coors still makes it one of the easier places in which to hit a dinger, and fantasy owners continue to stockpile Rockies players on their rosters every spring. But given the effect it's had on Coors, what does this mean for Chase?
Bigger Effect In Arizona
Nathan argued that the humidor could be even more impactful in Arizona than it has been in Denver. The reason? An even greater lack of humidity in the desert.
A humidor that stores balls in an environment of 50% humidity means the balls will have absorbed more moisture than normal, which makes them a bit heavier and reduces their lack of "bounciness," according to Nathan.
"I am very comfortable saying that, with the humidor running at 50 percent and 70 degrees Fahrenheit, there will a reduction in home run production at Chase by 25-50 percent."
Nathan noted that a baseball with more moisture in it could reduce exit velocity speeds by up to four miles per hour, which would decrease the total number of dingers smashed out of Chase by a whopping 47%. Nathan's full write-up of his study is well worth your time and can be found here.
If Nathan's calculations of a 25-50% drop in homers at Chase Field are accurate, it would have a substantial effect on fantasy. In DFS and season-long fantasy leagues, users likely wouldn't be so quick to target batters who are suiting up in Arizona but may not be as afraid to go after a starting pitcher who toes the mound at Chase Field.
Paul Goldschmidt is still going to be one of the first five players selected in any fantasy draft, and that's never going to change. A.J. Pollock (with an average draft position -- ADP -- of 58th overall) is currently the 18th outfielder being taken, and perhaps you drop him down a couple spots because fewer of his batted balls might find open spaces. However, his game relies on speed, so the effect on him won't be as great.
But this would be a major downgrade for Jake Lamb, who hit 30 homers last season for Arizona but plays at a position that is stacked with other options. His ADP is currently 106, putting him in the middle of the eighth round in 12-team leagues as the 12th third baseman selected on average. You could bump up Miguel Sano or Mike Moustakas (depending on where he signs) over him as a result. Newly signed Jarrod Dyson's BABIP could take a hit, as well, although he's only being drafted in really deep or NL-only leagues. This also makes the landing spot for Steven Souza -- acquired in a trade on Tuesday -- less enticing, though he should get a boost in moving away from the Tampa Bay Rays' stripped-down offense.
As for pitchers, Zack Greinke (42nd overall ADP) and Robbie Ray (47th) are currently the 12th and 13th starting pitchers being taken. They could potentially get bumped up a spot, although where they are seems about right, even in a better pitcher's environment.
In the middle tier is Zack Godley, who broke out last year with a 3.37 ERA over 155 innings. He was a trendy sleeper pick even before this news broke. The price may seem high with an ADP of 121st overall, but there are now even more reasons to believe Godley could duplicate last year's performance.
Likewise, Taijuan Walker is currently being selected 204th overall, the 55th starting pitcher off the board. This would put him in the 17th round. It makes sense that he would leapfrog above pitchers like Kevin Gausman (ADP 198) ,Cole Hamels (ADP 194), Dylan Bundy (ADP 182) and others in this tier of starters where you're looking to get a steal. Patrick Corbin, 244th, also would move up boards a couple rounds.
You're probably not going to change how you value Arizona's stars, but the mid-range offensive players should probably be bumped down a bit, while the mid-rotation starters could probably be taken a round or two earlier.
But don't go overboard. While Nathan's studies predict that a humidor will have a more severe effect on offense than it has had in Coors, it has yet to play out in the real world. It is just a prediction. This should simply be a consideration when determining between pitchers and hitters of similar abilities at similar draft positions