Chiefs’ Arrowhead Stadium has weird night-game quirk. Will recent move change that?

When the ball bounced off former Kansas City Chiefs receiver Marquez Valdes-Scantling’s hands, it only took a few minutes for Tyreek Hill to come to his defense.

Hill played for the Chiefs from 2016-21. And from previous experience, he knew the play that Valdes-Scantling tried to make during the Chiefs’ home Monday Night Football loss to the Philadelphia Eagles last November was anything but simple.

“Everybody thinking that catch easy at night in them lights,” Hill posted on social media.

The domino effect from there turned out to be pretty fascinating, as the Chiefs prepare to host another Monday Night game against the New Orleans Saints on GEHA Field at Arrowhead Stadium.

Hill’s words sparked a question, then an NFL study.

And Tom Bliss, data scientist at the NFL, believes there’s something about Arrowhead Stadium at night that fans should know.

“This is one of the coolest things,” Bliss told The Star, “that I think we have found.”

‘A pretty drastic difference’

Bliss has long been fascinated by the idea of stadium effects in the NFL — even if it’s something that isn’t talked about nearly as much as other sports.

There’s good reason for that. Baseball has different walls and playing dimensions, for instance, making it drastically different to play in Yankee Stadium compared to the Royals’ Kauffman Stadium. In soccer, varying field and sideline dimensions can also affect play and scoring.

All NFL stadiums, however, seem like they should be about the same. Fields are 100 yards long with 10-yard end zones and identical-sized goalposts, meaning the variation from one place to the other doesn’t seem like it would change much.

This is why Hill’s post sparked Bliss’ curiosity. Could there be a chance that Hill was right — and maybe it was tougher to catch passes at Arrowhead?

“This was something we thought, ‘Maybe there could be something there,’” Bliss said.

Shortly after that Monday Night Football game, Bliss broke down the data with NFL colleague Michael Lopez. They looked at NFL games from 2016-2023, measuring player drop rates on early-afternoon, late-afternoon and night games at each stadium.

When Bliss finished the analysis, the result took him by surprise.

The stadium that Hill talked about was the one with the craziest situation.

During night games, Arrowhead had a drop rate of 10.3% for both teams — the highest of any stadium and time combination and well above the league average of 6.7%. Interestingly, the drop rate at Arrowhead for early afternoon (6.5%) and late-afternoon games (6.7%) remained right around the league average.

Based on statistical measurements, Lopez later shared that the likelihood of Arrowhead’s higher drop rate being due to chance was roughly 1 in 6,000. Bliss also believes the results are “unlikely” to be randomness.

“It’s a pretty drastic difference,” he said.

But what’s the exact reason for it?

Bliss has a few guesses, even if some aren’t scientifically based.

It’s also worth knowing this: An offseason change could alter this quirk in the future.

A ‘brighter, lighter’ future?

Chiefs tight end Noah Gray says the team’s pass-catchers have a tradition before each game: familiarizing themselves with a stadium’s lights.

Gray can list some of the interesting ones by memory. New Orleans’ Caesars Superdome has two sets of lights that encircle the field. Houston’s NRG Stadium, meanwhile, has two separate banks of lights to know about.

“There’s definitely different light fixtures around stadiums in the NFL that make it different,” Gray said Saturday in the Chiefs’ locker room, “but you kind of figure that out in pregame.”

So, is Arrowhead’s light setup different from others, perhaps causing more drops at night?

Gray said it’s difficult for him to tell. He said he loves playing at Arrowhead and has done it so many times now that he’s “used to it.”

Lights, however, seem like one of the most obvious factors that could make a stadium different from its counterparts at night.

And that’s why this drop pattern might be worth monitoring closely as this season progresses.

The Chiefs, according to vice president of corporate communications Luke Shanno, replaced their lights with new LED ones from Musco this offseason — a move unrelated to the NFL’s study from last season. The makeover, instead, was done as part of the stadium’s work to get to FIFA standards for the upcoming 2026 World Cup.

Before this offseason, Shanno said the Chiefs had regularly maintained their lights over the previous five years. The switch to LED lights, though, is new — and Gray said he’s noticed.

“It definitely seems a little different out there,” Gray said. “I feel like the old ones were more yellowy. The LED ones, I think, are a brighter, lighter color.”

Could the new light potentially reduce drops? The early data isn’t definitive.

According to Pro Football Focus, the Chiefs had three drops in their Week 1 night game at Arrowhead against the Ravens. Since then, they’ve played at home in the afternoon, at night in a dome and on the road in the afternoon; they combined for only two drops in those three contests.

So could it be the lights’ location, instead of brightness, causing an issue? Or maybe something else?

‘Everything is a million things’

Bliss believes a combination of factors is the likeliest answer.

“Everything is a million things,” Bliss said. “It’s never just one thing that’s affecting it.”

One of his non-scientific theories is this: Fans’ background color might have an impact.

Looking at his study, some of the highest drop rates at night were from home teams that had team colors that might blend in with a brown football: KC (red), Washington (brown), Cleveland (brown/orange) and San Francisco (red).

On the other end, the lowest drop rate at night was for Minnesota, and it could make sense that the Vikings’ purple fan colors would contrast nicely with the football in the air, making it easier to catch.

Chiefs receiver JuJu Smith-Schuster said he never noticed background fan colors while catching but said it was an “interesting” concept to think about.

Overall, he noted three instances when it was most difficult for receivers to catch: When the lights were in their eyes, when it was a shady game with a little bit of sunlight, and when a helmet visor affected vision.

He said Chiefs receivers hadn’t ever spoken about how it was more challenging to catch in Arrowhead’s night conditions.

“We just try to make the play and get the yards,” Smith-Schuster said with a smile.

Bliss said the study will remain on his mind as he watches Chiefs-Saints on Monday night.

More than anything, he finds it fascinating there are so many new ways to explore football while adding to our understanding of the game.

“It’s cool to know that things that you don’t even think about,” Bliss said, “might correlate with real football outcomes.”