PHOENIX -- The D-backs are in the process of building a humidor at Chase Field with the goal of improving the grip that pitchers are able to get on the baseball.
The only other humidor used in Major League Baseball is at Coors Field in Denver, which is the one Major League city with a higher altitude than Phoenix.
Major League Baseball guidelines say that baseballs should be stored at 70 degrees with about 50 percent humidity. That isn't possible in the dry desert air, particularly during the hot summer months without the help of a humidor.