Humidor cancels out altitude

DENVER -- The biggest attraction at Coors Field on Friday was not David Ortiz, Daisuke Matsuzaka or Todd Helton. The biggest attraction was a small room used to store baseballs.

As the Boston Red Sox took batting practice and the Colorado Rockies dressed for their workout, Rockies publicist Jay Alves offered a guided tour of the Coors Field humidor. Some two dozen reporters abandoned their interviews and rushed to follow Alves into a hallway near the Colorado clubhouse, all for a peek at the famous humidor.

“It’s probably about as big as a jail cell,” Colorado pitcher Matt Herges said, “not that I’ve ever been in one.”

There are two adjacent storage rooms, with silver doors that shut tight. They keep the beer in the large room, the baseballs in the small room. The Rockies can store up to 400 dozen baseballs inside the humidor, nine feet wide and nine feet deep and seven feet high, with temperature controlled at 70 degrees and humidity at 50%.

The Rockies had longed to control the arena baseball element of Coors Field, studying field dimensions and weather patterns, when an employee in the stadium engineering department noticed his leather boots had shrunk at altitude. As General Manager Dan O’Dowd told the story, the team tested baseballs and noticed similar shrinkage. The balls got smaller and harder, and so they traveled farther.

Voila: the humidor.

“We kept attributing everything to altitude,” Manager Clint Hurdle said.

Said O’Dowd: “I really think it’s one of the biggest things that has happened for our franchise. It normalized the game.”

Batters hit .286 at Coors Field this season, the highest in the majors, in part because of the vast outfield that enables balls to drop in for singles and doubles. But Coors Field ranked 10th in home runs per game, at 2.26.

O’Dowd laughed at the question of whether the humidor and its effects have made free-agent pitchers more receptive to signing with the Rockies.

“No,” O’Dowd said. “Free-agent pitchers are more receptive to money -- length [of contract] and money. I don’t think that’s going to change.”

With the designated hitter not in effect here, Boston Manager Terry Francona said Ortiz would play first base tonight, forcing first baseman Kevin Youkilis to the bench. Francona said rookie center fielder Jacoby Ellsbury would lead off, followed by rookie second baseman Dustin Pedroia. . . . Red Sox chairman Tom Werner invited pitcher Matsuzaka to his home for dinner last winter, showing him a replica of the World Series trophy and inviting him to sign with the Red Sox and help the team win another one. Said Matsuzaka, who starts tonight against Colorado’s Josh Fogg: “When I saw that trophy, I felt it was very beautiful, and I was very moved. I definitely wanted to hold that trophy in my hands one day.”

bill.shaikin@latimes.com