Looking back at how the “environmental chamber” on the 20th and Blake changed baseball – Advice Eating

Former Rockies right-hander Jason Jennings chuckled at the absurdity of the question.

“Yes, of course the humidor made a difference,” he said. “It made a 100% difference. For Pitcher, it was about survival.”

It’s been 20 years since Jennings became the unchecked winner of National League Rookie of the Year, and 20 years since the Rockies began storing baseballs in a humidor to bring some semblance of baseball sanity to Coors Field.

In fact, it was Sunday 20 years ago when the Denver Post published the story.

“At last the Colorado Rockies found a way to tame baseball at height,” wrote Mike Klis, former beat writer for the Post Rockies. “This is not a rehash of the Blake Street Bombers dismantling. The Rockies didn’t suddenly draft a roster of 100-mph pitchers, either. And no, the groundsmen didn’t find and reinsert the elevation plug at Coors Field, as manager Clint Hurdle suggested last week.

“This is about the humidor. A baseball humidor.”

Or, as Keli McGregor, the late Rockies team president, preferred to call it “an environmental chamber.”

The Rockies began building the chamber after the 2001 season. On March 31, eight days before their home game against Houston, the Rockies began wetting baseballs.

Now, 20 years later, every Major League Baseball team baseballs in a humidor to create an even playing field, regardless of the temperature and humidity at each ballpark. MLB decided to set the humidor to one setting — 70 degrees and 57% relative humidity — at all parks except for the mile-high Coors Field, which uses 65% relative humidity.

“I had no problem with it before, and now I can see the value in it,” said Dr. Meredith Wills, a sports data scientist with a Ph.D. in astrophysics. “We’ve seen it work in dry conditions in Colorado and Arizona. The humidor will dry out the baseballs in wetter areas.

“The humidor is designed to mimic the bounce of the ball off the bat in any park. The point of the humidor is that the spheres should react the same and all end up having roughly the same weight.”

But now, like 20 years ago, there is controversy over how MLB cares for its baseballs and how that is affecting the game.

“Nobody knows,” Dodgers pitcher Clayton Kershaw, a three-time Cy Young Award winner, recently told the Los Angeles Times. “Whatever MLB says, they don’t know either. … Every way they rub the ball is different. Every ball they make is different. Every way they put the mud on the ball is different. Definitely check them out guys now. It’s all a bummer. Nobody knows. Whatever MLB thinks is going to happen, it will likely be the opposite.”


MLB’s first humidor was the brainchild of Tony Cowell, an electrician and team foreman who helped build the 20th and Blake stadium. Coors Field’s notorious reputation bothered him.

RJ Sangosti, The Denver Post

Tony Cowell came up with the idea for the humidor on May 5, 2022 at Coors Field in Denver. Cowell holds the baseball he cut open with his bandsaw when he first thought of the idea of ​​the humidor all those years ago.

After the 2001 season, when McGregor reached out to Rockies staff for suggestions on how to improve the organization, Cowell began brainstorming. The idea for a humidor came to him during a hunting trip at 10,000 feet.

“I was moose hunting in the Flat Top Wilderness when the thought came to me,” recalls Cowell, 60. “I was hunting up there and I was wearing these old leather hunting boots and they got all wet and dirty .

“Then they dried out and got really uncomfortable. I remember thinking, ‘I hate how these things shrink when they dry out. So I put two and two together, so to speak. “Wait a minute, my boots are leather. The outside of a baseball is made of leather. It’s not just about the height. The baseballs are drying out, as are my boots.’ ”

There’s no question that the humidor at 20th and Blake was a turning point.

“I really didn’t have any expectations of how effective it would be, but I certainly had hope when we installed it,” said former Rockies general manager Dan O’Dowd. “The humidor didn’t necessarily help lower our team’s ERA after the humidor, but home runs went down dramatically. It definitely helped normalize the game to some extent.”

But current Rockies left-hander Kyle Freeland, who was born and raised in Denver, doesn’t see the humidor as a complete salvation for pitchers in Coors, especially when hot, dry weather hits in July and August.

“Baseballs at sea level still feel a little softer and a little bit grippier than here,” Freeland said. “And in my opinion, when the balls come out of the humidor and sit in the bags where they’re kept before the game, it doesn’t have (as much) an impact.

“Because I get a baseball from the umpire and it feels slippery and chalky and I don’t want the mud to settle on the leather. So you have to rub it with saliva, sweat or whatever to get a good handle on it. The ball is still different from LA or San Diego.”

Still, 20-year statistics show that the humidor has helped Rockies pitchers while also hurting the club’s sluggers.

From 1995 to 2001, Colorado’s average team ERA was 6.14, and the pitching team gave up an average of 126.7 home runs per season. But from 2002 through 2021, average ERA shrank to 5.06 and home runs dropped to 98.8 per season.

Before the humidor, the Rockies’ batting average at Coors was a .328 and they were hitting 128.3 home runs per season. After the humidor, the average dropped to .295 and home runs dropped to 103.2 per season.

Of course, there were some other elements at work as well.

In response to the so-called “steroid era,” MLB introduced league-wide performance-enhancing drug testing in 2003.

In 2019, Juiced Baseballs resulted in 6,776 home runs hit during the regular season, which broke the previous MLB record set in 2017 by almost 11%. Rockies pitchers served 144 home runs in 2019, which was the second-highest in Coors Field’s history using 2001 staffers. Colorado’s 1999 Pitching Corps gave up 159 home runs.

In that first year of the humidor, runs at Coors Field were down 11 percent across the board since 2001. More tellingly, the Rockies recorded their lowest ERA (5.47) and batting average (.312), easily eclipsing the 5.67 mark in 1997 and .316 in ’95.

Former Rockies first baseman Todd Helton gave the humidor a thumbs-up, telling The Post at the time, “I like the flow of the games. It’s a lot more fun for the fans than for us. It’s actually easier to beat this way when games don’t last that long. You don’t stay on the field forever. If our mugs like it, I like it. That’s all I care about.”


Jennings was fine on his first start at Coors in September 2001, but his next outing was a disaster. He lasted only 1 1/3 innings, giving up seven carries on seven hits, with two walks against the Padres.

For Jennings and other pre-humidor-era Rockies pitchers, the biggest problem wasn’t that baseballs continued to be carried at altitude. Their complaint was that they couldn’t grab the ball properly.

“The problem was that baseballs were shrinking,” Jennings recalled. “The balls dried up and you couldn’t feel the seams. it was crazy I mean, it was like, ‘You expect us to take on the Barry Bonds of the world, a mile above sea level, with a cue ball?’ That’s basically what we threw.

“The (clubhouse employees) were rubbing the balls with the mud they were using and that didn’t do us any good. All it did in Colorado was essentially turn the mud into a dry powder. Then we would have to wipe that away.”

Jennings said he got better at grabbing the ball starting in 2002, when he finished with a 16-8 record and a 4.52 ERA.

On June 20, 2006, Jennings and assists Tom Martin and Brian Fuentes scored a one-hit 6–0 shutout against Oakland at Coors Field. Athletics manager Ken Macha, on the wrong side of Denver’s first one-hitter, suspected a conspiracy.

“I still think the (humidor) should be investigated,” Macha said. “Maybe we should do that in our stadium. The ball is the same weight but they’re sitting in there and they’re getting moisture so I don’t understand. It’s like you pull your golf ball out of the water – find one out of the water – and you hit it.”

In 2010, Giants Cy Young Award winner Tim Lincecum essentially accused the Rockies of cheating and implied they used non-humidor baseballs when they hit the plate.

“(Expletive) juiced ball. This is (expletive),” Lincecum was caught on camera as he said.

After Giants general manager Brian Sabean complained, MLB ordered changes to how baseballs were overseen at Coors. Under the new procedure, the umpires began carrying bags of balls out of the humidor and placing them in Colorado’s dugout, where they remained in the umpires’ field of view.

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