Alan Nathan is stumped.

A retired professor emeritus of experimental nuclear physics at the University of Illinois, Nathan no longer studies collisions between subatomic particles. These days he spends his time examining collisions between a ball and a bat, establishing himself as one of the foremost experts in baseball physics.

“From a physics point of view, it’s sort of all the same thing,” he said.

But even Nathan, who has a Ph.D. in physics from Princeton University, is curious as to why a home run ball has never hit the famous Baltimore & Ohio Warehouse at Camden Yards during a game in the ballpark’s 33 seasons.

“It’s within the realm of possibility,” he said.

The imposing, eight-story brick building was completed in 1905 to serve Camden Station, but it found a new purpose in 1992, providing Oriole Park with an iconic backdrop. By setting the edge of the playing field within striking distance of Eutaw Street, stadium designers expected the warehouse to receive its fair share of ricochets. In fact, windows on the second and third floors were refitted with shatter-resistant glass with the expectation that home run balls would make their way up there.

“We really did think the warehouse was going to be in play more often than it was,” said Janet Marie Smith, who directed the design of “The Ballpark That Forever Changed Baseball.”

But it never happened — in a game, at least.

You need a little lift

One hundred and thirty-one baseball-size plaques dot Eutaw Street, stretching from the area beyond the right-field foul pole to Boog’s BBQ beyond the center-field bleachers, but only one pockmarks the warehouse’s exterior. Ken Griffey Jr.’s majestic shot during the 1993 Home Run Derby, when the All-Star Game was in Baltimore, is immortalized by a marker about two-thirds of the way up a white column on the warehouse’s ground floor.

Ryan Comes was a wide-eyed 6-year-old attending the Home Run Derby with his father in 1993. He, like the nearly 50,000 other fans in attendance that day, remembers Griffey’s homer, but he had no idea he was witnessing an event that wouldn’t occur for at least another three decades. After all, the ballpark had opened only 15 months prior.

“I don’t think either of us thought that, 30 years later, no one would have actually hit it in a game,” he said.

Comes, who just so happened to play baseball at the same high school as Orioles general manager Mike Elias, is now an associate professor in the University of Delaware’s physics department. Intrigued by my query, he constructed a program on Microsoft Excel to determine what it would take for a ball to reach the bricks. But he ran into issues when failing to account for the spin of the baseball.

“The effect of spin on a ball leaving the bat is enormous,” he said.

Fly balls carry backspin, which not only allows them to fly farther but also to rise. This is called lift, and it’s why the ideal launch angle for a home run is 25 to 30 degrees, not 45 degrees.

But on the other end is drag, which pulls the ball in the opposite direction. Environmental factors such as air temperature, humidity, air pressure and wind conditions all have a say in how far a ball will travel. In some cases, their influence can be dramatic.

The conditions need to be perfect

Most fans understand the impact of these environmental factors. Routine fly balls in April become home runs in July because warm air is less dense than cold air. More long balls are hit in Denver than in San Francisco because air molecules are farther apart at high altitudes than at sea level.

Sig Mejdal is in the predictions business. As the mastermind behind Camden Yards’ (twice) reconfigured left-field wall, the Orioles assistant general manager spends many of his days on the warehouse’s eighth floor forecasting home run totals. But Mejdal, who got his bachelor’s degree in mechanical engineering and aeronautical engineering at the University of California, Davis, admits he hasn’t run simulations to determine how hard it would be to hit the warehouse.

“It’s interesting, but it hasn’t made it to the top of our to-do list,” he said. “It enters our mind, probably like every other fan, when someone hits a monster shot to right field.”

Still, Mejdal considers it an intriguing thought experiment. When pondering the proper conditions required for such a titanic shot, Mejdal pointed to a game in June 2022, when Orioles outfielder Austin Hays became the seventh player in Camden Yards history to reach the second deck in left field on a home run.

What made the feat seem more impressive was that Hays drove his solo shot through a steady rain. But the watery conditions may actually have helped the ball sail farther, Mejdal said.

“The humidity and the rain, that’s a lot of H2O,” he said. “So the hydrogen is replacing the nitrogen in the air. Hydrogen is a much lighter atom, so the ball is colliding with lighter atoms on the way there. And, even if there’s some rain in the way, I guess in this trade-off hydrogen is enabling that ball to travel not just over the fence but land on the [second] deck.”

The seams of a baseball can also absorb moisture, adding to the object’s weight and increasing its distance. (For this reason, MLB mandates that all 30 teams store game balls in humidors for at least 14 days before use in an effort to limit humidity and standardize ball flight.)

The final environmental factor to consider is one that is nearly impossible to predict: wind. A strong breeze could push a home run ball along its trajectory, but it has to be blowing in the right direction. Plus, the stadium is an impediment.

“In the absence of the stadium, there could be steady wind in a certain direction,” Nathan said. “But the stadium itself affects the speed and the direction of the wind in funny ways that are very hard to predict.”

So the ideal setting for the kind of long ball required for this exercise would be a hot, muggy afternoon or evening in Baltimore — in other words, an average summer day in Maryland — with the wind blowing out to right field and a light drizzle falling.

On July 12, 1993, when Griffey hit his famous shot, records show it was 92 degrees in Baltimore, with a 12-17 mph wind blowing from the northwest (toward the right-field corner) and humidity over 70%. A perfect setting for long home runs.

Now, let’s say all of the necessary conditions are met during a July game at Camden Yards. A left-handed hitter strolls to the plate and whacks a pitch high over the right-field wall. How far would that ball need to go to hit the warehouse?

Well, it depends.

The warehouse is farther than it looks

The warehouse, which spans 1,116 feet in length and 51 feet in width, may look temptingly close to left-handed hitters walking into the batter’s box, but it is deceptively far.

The warehouse’s closest point to home plate in fair territory is directly down the right-field line. The distance from home plate to the foul pole is 318 feet. Continuing along that line, it’s about 108 feet to the base of the warehouse. Add them up, and the warehouse is 426 feet from home plate.

But a ball projected by MLB’s data tracking tool, Statcast, to go 426 feet down the line wouldn’t get the job done. In actuality, you’d need one that’s projected closer to 460 or 470 feet. Why?

Statcast, which was introduced in 2015, is the system MLB uses to track every ball and every player during games. Few people have more knowledge about Statcast than Mike Petriello, an MLB.com writer who has hosted podcasts on the technology. And few things frustrate Petriello more than misconceptions that persist about Statcast’s projected batted-ball distances.

“People think home run distance is only exit velocity plus launch angle. It’s really not,” he said. “People post [on social media] combinations of those two things and say, ‘Well, this ball went 10 feet shorter, we got ripped off.’ Well, yeah, but wind and humidity …”

I told Petriello I pictured Statcast’s process as a complex equation in which the variables are the conditions and the sum is the projected distance. But he was quick to push back on this notion.

“A home run distance is not a formula of any inputs,” he said. “It’s a tracked trajectory as far as it can possibly go.”

Major League Baseball uses lidar, which stands for light detection and ranging, to scan and create renderings of all 30 big league ballparks. Using these maps, the league says Statcast can trace the ball’s path and identify its landing spot with accuracy “down to 3 mm.”

But Statcast isn’t looking for the distance between home plate and the landing spot when projecting how far a ball traveled. It’s looking for the distance between home plate and the location the ball would have landed if it had continued along its arc and come to rest on flat ground. The ball can be tracked only as long as it’s moving, so Statcast’s formula takes over once it reaches its landing spot.

“Assuming that it is tracked most of the way, a formula fills in the gaps,” Petriello said. “But, at a certain point, there’s only so many different outcomes that could happen. It’s not like, once the ball is 400 feet away, now it’s getting more exit velocity.”

Oriole Park’s playing surface isn’t on flat ground; it’s 21 feet below street level. The 426 number would represent only a ball’s landing spot. It doesn’t take into account the added elevation. This is why the numbers stamped on the plaques along Eutaw Street are often different from those produced by Statcast.

Petriello estimates a home run ball would need a Statcast-projected distance of 460-70 feet to reach the warehouse. Has any such ball been hit at Camden Yards since Statcast’s inception?

Yes, in fact.

A ball hit to right field doesn’t go as far as a ball hit to center

On June 11, 2023, Gunnar Henderson really got hold of one.

With two on and two out in the bottom of the seventh inning, Henderson turned on a full-count slider from Kansas City Royals righty Jackson Kowar. The resulting collision sent the ball rocketing off the bat at 113.8 mph for the shortstop’s ninth home run of the season. The ball bounded off Eutaw Street and met the warehouse on one hop. Statcast’s projected distance: 462 feet.

David Levine has the image of Henderson’s titanic blast cemented in his memory.

“I just like watching it whenever possible,” he said. “It’s absolutely beautiful.”

Levine, a 28-year-old Orioles fan with a Ph.D. in mechanical engineering and applied mechanics from the University of Pennsylvania, included a clip of the dinger on a 10-page PowerPoint presentation he put together for our Zoom meeting. One of a handful of physicists who answered my call to action, he selected Henderson’s home run as a test case in hopes of solving this riddle.

Alan Nathan’s trajectory calculator, which is publicly available on his website, is a souped-up Microsoft Excel file that allows users to project batted ball distances, given they input all the necessary conditions. Levine looked up the weather on that day in June — 87 degrees, 40% relative humidity — and plugged all the factors into the trajectory calculator. Then, he isolated different variables, hoping to chart the easiest path for the ball to reach the warehouse. His first thought was to change the direction of the ball, pushing it farther toward the right-field corner and eventually onto a collision course with the warehouse.

But there was a nagging scientific truism working against him, and it was one Nathan himself proved: A ball hit to dead center field travels farther than a ball hit to one of the corners. The reason for this phenomenon, Nathan has concluded, is sidespin, and it can knock as much as 12 feet off a ball’s projected distance.

“That could be the difference between hitting the warehouse or not,” Levine said.

“You can think of backspin; you can think of sidespin. Those two things are going to be kind of working against each other when we’re talking about this. If you’re hooking the ball to try and hit the warehouse, you’re gonna have to put some sidespin on it and that’s gonna hurt you.”

It may seem counterintuitive, but the more a batter pulls the ball, the more he sacrifices in distance. That 470-foot target distance is a lot harder to reach in right field than it would be in center.

Levine concluded that, at the original angle of Henderson’s home run, the warehouse is about 481 feet from home plate. So, instead of changing the ball’s trajectory, he isolated a different factor — exit velocity. Levine increased the exit velocity until the projected distance hit 481, eventually arriving at 118 mph.

Since Statcast debuted in 2015, only 14 players have hit home runs that have gone 118 mph. New York Yankees sluggers Giancarlo Stanton and Aaron Judge are the only players to do it more than once, and despite ranking in the 98th percentile in average exit velocity last season, Henderson has yet to hit that particular milestone. But he’s just 23 years old and figures to get stronger as he matures physically. A 118 mph homer is not out of the realm of possibility.

And, if Henderson doesn’t do it, maybe one of his teammates could.

You need an extremely powerful lefty

Mike Elias loves his lefties. The 2023 MLB Executive of the Year built the best farm system in baseball by drafting left-handed-hitting position players early and often — Adley Rutschman (switch hitter), Henderson, Heston Kjerstad, Colton Cowser, Jackson Holliday, etc. Elias knows how to play to the strengths not only of his scouting department but also the features of his home ballpark. When Elias and Mejdal decided to move the left-field wall back, the Orioles’ lefty-heavy lineup gained an even greater advantage.

Baltimore has had its fair share of power hitters over the years. Chris Davis, Manny Machado and Adam Jones were linchpins of an Orioles lineup that led baseball in home runs in 2013, 2014 and 2016. But no one on those teams ever reached the warehouse.

“The fact that Chris Davis never did it is sort of an indicator of just how difficult it is,” Comes said.

But if there’s an Oriole who could reach the warehouse, he should be on this current roster. Baltimore mashed 235 homers in 2024, second only to the Yankees in MLB. Henderson’s 37 were ninth most in baseball, while fellow lefties Cowser, Cedric Mullins and Ryan O’Hearn combined for 57. Twelve of Rutschman’s 19 homers came from the left side of the plate. And, even though the O’s most prolific power hitter, Anthony Santander, departed in free agency, they’re counting on more production from two highly touted prospects: Holliday and Kjerstad.

Kjerstad has only six big league homers to his name, but he is among the best pure power hitters in the organization. Hitting the warehouse is something that has crossed his mind during batting practice.

“As a left-handed hitter, you see it every day,” Kjerstad said. “You go out there, you definitely think about it.”

Henderson and Rutschman have already reserved spots on Eutaw Street. Kjerstad, Cowser or Holliday could soon follow. But, for all the home runs this talented group figures to produce in their careers, there’s only so much a hitter can control.

You have to get ‘pretty darn lucky’

Hitting a home run is hard enough. You need the requisite exit velocity — about 90 to 120 mph — and launch angle — about 25 to 35 degrees. Even under the perfect conditions, reaching the warehouse would take a miracle.

“It’s not crazy impossible,” Levine said. “It’s just you need to get pretty darn lucky with the ambient conditions on top of having a ball that’s hit super hard in the correct window of exit velocity and launch angle.”

“It’s almost, you don’t wanna say it’s impossible,” Kjerstad said. “But there have been a lotta great players that are playing here now with power and a lot of great players in the past and it still hasn’t happened.”

Of course, there’s an equal chance an opposing player is the first to ding the warehouse. Juan Soto and Shohei Ohtani have earned plaques along Eutaw Street, and each new wave of superstars produces bigger and stronger athletes than the previous one.

Camden Yards has already seen more than 2,500 games, and we’re still waiting for our first warehouse homer. That’s a large enough sample for many to give up on the possibility. But the science tells us there’s a chance.

“In a way, it’s a little surprising that it hasn’t been hit yet,” Nathan said.

Photos shown behind scrolling text by Baltimore Banner photographer Ulysses Muñoz.