As the Colorado Rockies wrap up celebrating their 30th anniversary, The Colorado Sun is taking an in-depth look at the team’s losing history and if there is hope for a turnaround. This four-part series breaks down the struggles and possible transformation.
Let’s say you are a major league pitcher. (The Show! Congratulations!)
And let’s say you have an average curveball. (Hey, we can’t all be Phil Maton.)
If you throw that pitch in almost any major league stadium, the spin you put on the ball will cause it to drop about 9½ inches and cause it to break sideways about 9 inches. But not at Coors Field, where air density is only 82% of what it is at sea level.
There, in a stadium five times higher than any other in Major League Baseball, your curveball will drop only about 7 inches and will break sideways by the same amount. That may not seem like anything — though it is roughly 25% less movement. But in a game defined by incremental differences over a massively long season, it can be everything.
That curveball in other stadiums might just catch the bottom corner of the strike zone, an unhittable yakker. At Coors, 2 inches higher and 2 inches closer to the center of the zone, it’s a meatball. Chomp, chomp.
And this helps explain the vexation that the Rockies pitching and coaching staffs have experienced for the past 31 years trying to figure out how to make what is successful everywhere else work in baseball’s weirdest funhouse.
Former Rockies manager Jim Leyland in 1999: “In Colorado, your stuff automatically is not as good.”
Former Rockies pitcher Darren Holmes in 2014: “My best pitch was my curveball, and it wasn’t doing what it was supposed to do. I couldn’t get it down in the strike zone to save my life.”
Former Rockies pitcher Mike Hampton, still the team’s biggest-ever free agent pitcher signing, in 2017: “I was going to prove it could be done or die trying. I almost died trying.”
Baseball is a sport raised at low altitude. The game’s mythical birthplace, Cooperstown, New York, sits at 1,200 feet above sea level, and it’s been all downhill from there.
After Coors Field, the majors’ next-highest stadium is in Phoenix — at a little over 1,000 feet above sea level. (When the Oakland Athletics move to Las Vegas, their new home will become Major League Baseball’s second-highest. But even then, at around 2,000 feet above sea level, it is still 80% lower than Coors Field.)
This means all the very fundamental things we know about how to play baseball — which pitches work in which situations, what hitters should bat in which order, what a normal score is, what the dimensions of the field should be, how the ball should be constructed — all were tested in low-altitude proving grounds. Drag them up to a mile high, and they go kablooey like an unopened bag of potato chips traveling over Loveland Pass.
“I was going to prove it could be done or die trying. I almost died trying.”
— Mike Hampton, on pitching at Coors Field
“Coors Field has been, since the early days of Coors Field, it’s a hitter’s paradise and it’s a pitcher’s nightmare,” said Alan Nathan, a University of Illinois professor emeritus who studies the physics of baseball.
So is this it? Is this the right-in-front-of-our-nose reason why the Rockies seem, as one writer for Baseball Prospectus put it, “stuck in a place where winning baseball seems close to untenable”?
“The Rockies have been playing at high altitude since the early-90s,” he said. “It’s hard to use that as an excuse, but anyway.”
But anyway …
Altitude makes it harder to throw good pitches …
Put on your lab coats, sports fans, because we’re about to get sciency.
In the 1800s, there was this German guy named Heinrich Gustav Magnus, who was a one-man research dynamo. He published 84 research papers in his life, spanning biology, chemistry and physics.
In 1852, he popped his masterpiece: a description of how a spinning object moves through air. Today, it bears his name: The Magnus effect. (Isaac Newton likely discovered it first two centuries earlier, but anyway.)
The Magnus effect is what makes Coors crazy for pitchers because it’s dependent on air density.
“The primary effect of traveling through air is air resistance or air drag,” Nathan said. “The ball has to push the air molecules out of the way.”
At lower altitude, this is harder because air is denser. That means the air exerts greater force on the ball, pushing it in the direction that its spin wants to take it.
For curveballs, with topspin, the Magnus effect is what makes the ball drop. But for hard-thrown four-seam fastballs, with backspin, the Magnus effect creates lift, allowing the ball to end up higher than it otherwise would just due to the effects of gravity. (All pitches drop between the mound and home plate, but the backspin on a good four-seam fastball makes it appear to “climb” as it reaches the batter.)
The lower air density at Coors Field means these effects are less. Curveballs break less, as we’ve already seen. But four-seam fastballs climb less. Rockies pitchers have seen about 3 inches less vertical movement on their four-seam fastballs this year when pitching at Coors Field versus when pitching on the road, according to Major League Baseball data.
… So Coors Field is brutal for pitchers
There was a time when the Rockies weren’t shy about going after some of the most sought-after free-agent pitchers on the market.
Darryl Kile. Denny Neagle. The aforementioned Mike Hampton, who signed an eight-year, $121 million contract in 2000.
Bombs, all, in the home of the Blake Street Bombers.
Those three pitchers are part of a curious fraternity of pitchers who had been all-stars prior to coming to Coors Field, only to have some of the worst years of their career — at least by traditional metrics, such as earned-run average — in Denver. Both Kile and Hampton rebounded to better seasons as soon as they left the Rockies.
What’s even more incredible is that advanced metrics, like ERA+, seem to validate that it was almost all the ballpark’s fault.
ERA+ tries to control for variables that can affect stats like ERA, including the ballparks where a pitcher is playing. It also standardizes performance across all pitchers, so it’s easy to see how one player compares to the league average. In this way, it’s a more fair stat.
Looking at those numbers, Hampton’s famously low lows in Colorado weren’t actually that low. In his first year in Denver, he had an ERA+ of 99. (League average is always 100 and higher is better.) The year after he left Denver, when his ERA dropped by more than a third, his ERA+ rose to about 10% above average. The only thing that changed is where he pitched his home games.
Batted balls fly farther, duh …
The more famous effect of altitude, of course, is how it can turn a baseball game into a backyard home run derby.
Four of the five longest home runs hit in Major League Baseball since 2015 have been at Coors Field, including two of the majors’ three 500-foot-plus dingers. And, again, it’s all about the physics.
The lower air density means there’s less resistance slowing down a ball hit into the air. The advent of complex data-gathering systems that can measure just about every aspect of a ball in flight have made this phenomenon even clearer.
Nathan said a typical home run in the majors — one hit with an exit velocity of about 100 mph, with a launch angle somewhere between 25 and 30 degrees — will travel about 400 feet at sea level. At Coors Field, the same ball would travel about 420 to 425 feet.
“That is an enormous difference,” he said. “That’s not theoretical. You can actually look at data.”
The Rockies knew this when they built Coors, though. So to compensate, they famously set the fences way back, creating a palatial outfield that is the second-largest in the majors. This creates more opportunities for bloop singles, but also for doubles and triples hit into the enormous gaps between outfielders.
Coors Field this year leads all major league stadiums in the stat known as “park factor” — essentially how much the individual characteristics of each ballpark juice or impair players’ performance. Coors has been the major league leader in park factor for all but four years since 1999.
And this effect, too, can be seen in the career stats of Rockies hitters. Just looking at batting average, players often improve significantly when coming to Denver.
Larry Walker was a great hitter before signing with the Rockies. But he became a superstar here. Meanwhile, hitters often see a slump when leaving Colorado — Troy Tulowitzki is a classic example, though injuries also played a role.
Again, using more advanced metrics tempers the picture. Except for his MVP year of 1997, Larry Walker’s OPS+ — a stat that, like ERA+ attempts to standardize comparisons across players — didn’t change significantly from the year before he came to Colorado to the year after he left. He was always well above average.
… But that’s not always helpful to hitters
One of the most underrated impacts of playing at altitude is that half the time you don’t play at altitude. Baseball seasons are split evenly between home and road games.
This means that not only do players need to adjust to playing in thin air, they also need to adjust when they go on the road and the baseball physics settles down.
This can be great for pitchers, who often find things a little easier. “On the road, I can grip it and rip it whenever,” former Rockies pitcher Jon Gray once said about his curveball.
But it can be a bigger switch for hitters. Pitches suddenly aren’t as easy to hit. Balls that might have been home runs at Coors become long flyball outs.
Since 2008, the Rockies have had the best home batting average in the majors. And the worst road batting average.
In 2021, the blog Rox Pile looked to see whether there was any data to support the so-called “Coors Field hangover.” That is the idea that Rockies hitters perform especially poorly in the first games of a road trip after having played a homestand.
The blog found that, over the prior five years, the Rockies had a .375 winning percentage in series where they went directly from playing at Coors Field to playing at sea level. The team’s overall road winning percentage in that time was .415.
So, is altitude to blame?
We talked to two baseball-mad scientists for this story — in addition to Nathan, we also spoke with University of Colorado mechanical engineering professor Peter Hamlington. And we asked both whether playing at altitude just makes it impossible for the Rockies to be good.
Neither took the bait.
Nathan said the altitude effects are known things, so they are something team leaders can plan around. Organize your farm system to produce nothing but altitude-inured mountain goats. Sign pitchers who are good at getting opposing hitters to swing and miss — taking out of the equation how far a ball can travel at altitude.
“One of the things that major league players are really, really good at is adjusting,” he said.
(The Rockies, of course, would argue that they have tried and are trying all of these things.)
Hamlington pointed out that, as tough as the altitude is for ballplayers in Denver, it could be worse. Denver’s dry air actually mutes some of altitude’s impacts because dry air is more dense than humid air. A city of Denver’s elevation in the tropics would produce even wilder baseball.
“It’s kind of hard at times to parse out what is due to the lower density of the air versus the lack of humidity versus the size of the outfield,” he said.
On top of that, altitude training should in theory give Rockies players a slight advantage over their competitors. Pitchers will fatigue less quickly. Hitters can recover faster from running the bases.
“Good general managers will try to put together a team that fits Coors Field, trying to take advantage of things that could be a disadvantage,” Nathan said.
So maybe altitude is the answer to the question of why the Rockies can’t win. Or maybe it’s just a convenient fall guy. A patsy. A cover story for a team still trying to find its way more than three decades after coming into being.
A narrative that explains so much, and yet so little.