Quarterback Tyler Bray faced a steep learning curve when he joined the Kansas City Chiefs in 2013. An undrafted free agent, he had to memorize a thick playbook, master the verbiage of a new offense and acclimate to the speed of the pros.

He also had to find a “cadence” — the combination of color and number that quarterbacks bark before the snap of the ball, like Blue 42 or Red 80. Bray had run a no-huddle offense at the University of Tennessee, which meant the snap was based on a physical cue like clapping hands or a leg kick. And while he hadn’t used a verbal cadence much before, it didn’t seem like a big deal.

But when he tried out White 80 in practice, Chiefs head coach Andy Reid told him to knock it off.

“You hold your ‘white’ too long,” Reid told Bray. “Choose a different color.”

Bray tried green, but that didn’t feel right, either. “And so for the rest of my career,” Bray says, “it was always Blue 80.”

In the modern NFL, where microphones blanket the field, there are few things more audible than the quarterback cadence. Before every play, Patrick Mahomes growls Blue 80 (or sometimes White 80). Tom Brady hollered Green 18. Brett Favre yelled Blue 58. So did Aaron Rodgers, when he wasn’t saying Green 19. Hollywood followed suit. In “Ace Ventura: Pet Detective,” Jim Carrey went with Blue 42.

Sometimes the color-number combo means something. Sometimes it’s nothing more than a rhythmic way to initiate a play.

“This is something that quarterbacks never want to give up,” former NFL QB Matt Hasselbeck says. “Because the mystery of it is really important.”

There is, however, one constant: Most NFL quarterbacks have no clue where or why or how it began.

“I don’t know who started it, at all,” Seahawks quarterback Geno Smith said.

“I hope you didn’t expect me to know that,” the Giants’ Drew Lock said, laughing.

“It’s just been like that forever, honestly,” Vikings quarterback Sam Darnold said. “I don’t know why.”

There is a perfectly reasonable explanation for why color-number cadences exist, though, and the story spans the evolution of football.

In the fall of 1890, 3,000 people gathered at Sportsman’s Park in St. Louis to watch the University of Missouri play Washington University of St. Louis. It was the first football game in Mizzou history, and according to the Columbia Missourian, the afternoon was marked by a clear and cold forecast, the clanking of cowbells, the tooting of tin horns and locals who arrived at the game via farm carts, phaetons and surreys.

On the first series, the quarterback from Washington University began yelling a series of numbers — “31, 49, 87, 12” — to communicate plays. Mizzou’s team froze and looked to the referee. The game stopped. The officials conferred.

Was yelling numbers like that even legal?

Turns out, it was, but it was such a new part of the sport that Missouri’s players could be forgiven for their ignorance.

Just eight years earlier, in 1882, a group of players from Yale’s football team met at the duplex of Walter Camp to talk strategy. At the time football was a chaotic, random mess, more rugby than modern football, a mad scrum in a cloud of dust. But in 1882, Camp proposed the five-yard rule, which required teams to gain five yards in three downs to retain possession. With the addition of the five-yard rule came lines on the field, giving shape and form to the sport.

Camp and Yale’s players believed the new rule would make coordination and strategy essential, so they met at Camp’s duplex to talk about it. That day, Camp, often called the Father of American Football, wrote down five signals — believed to be the first ever recorded. Each signal consisted of a phrase. One signal, “Play up sharp, Charlie,” meant that Yale quarterback Henry Twombly would receive the snap and toss the ball to an end for a sideline run.

“Camp had to make up plays and make up signals,” Twombly later said. “He was in an entirely new field. There were no T formations, single or double wings. There was no coach and no football player that knew anything about this new, mysterious game.”

In 1889, Amos Alonzo Stagg, a player for Camp at Yale and later a legendary coach himself, claimed Yale switched to numerical signals for the first time in football history (There is some dispute about that. Historian Alexander Weyand credited the Pennsylvania Military College with creating a numerical signal system in 1887 using the cadets’ serial numbers to indicate who would receive the ball). Either way, by the 1890s signals had turned numerical, and it was common for quarterbacks to initiate a play by barking out numbers.

As defenses started to catch up, however, the signal system became more complicated. Coaches designated their halfbacks and holes along the line by number, offering a code for running plays. And with the invention of the huddle, teams started to rely on “automatics” – or audibles – to change plays at the line of scrimmage. Strategy begat mathematics: a quarterback might call play 28 in the huddle, then change it by shouting “add three” or “subtract seven” at the line.

“Football threatened to become an advanced course in mental arithmetic,” Stagg later said.

Then came along a young coach with a law degree and a new way of thinking.

Terry Brennan was an unlikely coaching visionary. An All-American halfback at Notre Dame in the late 1940s, Brennan majored in philosophy before earning a law degree at DePaul. When he succeeded legendary coach Frank Leahy at Notre Dame in 1954, his only head coaching experience had come at a Chicago high school.

He was just 25 years old.

At one point in the 1950s, Brennan attended a coaching clinic led by Oklahoma’s coach Bud Wilkinson, who had turned the Sooners into a powerhouse. Wilkinson’s famous Split T offense relied on the numerical signal system, and while Brennan admired Wilkinson and his success, he thought there could be a better way.

“You can teach any system of football and follow it to the letter,” he once said, “but I don’t believe in following it out the window.”

Brennan believed games were lost by error, so he wanted to simplify the game as much as possible. He worried addition and subtraction distracted linemen and created avenues for mistakes. To solve the problem, Brennan came up with what he called the “live color” system.

Each play in Notre Dame’s huddle was preceded by a color. If the quarterback said Red 28 in the huddle, it meant “red” was the live color. If he shouted any color other than red at the line, it was a dummy call. But if he yelled Red 17, his teammates knew the play had been changed from 28 to 17.

The color-number system spread like fire, and while it’s hard to say definitively that Brennan was the inventor, he was at minimum one of the early pioneers. It spread fast across college football and trickled up to the professional ranks, too. When Paul Brown coached the Cincinnati Bengals, the team always used the same live color: brown. When Hasselbeck’s father Don played tight end for the New York Giants, Bill Parcells preferred black.

In a relatively short amount of time, quarterbacks shouting a color-number combo at the line was the norm. Decades later, the color-number cadence still has meaning, but not in the way Terry Brennan intended.

When Matt Hasselbeck became the Green Bay Packers’ backup in the late ’90s, the coaching staff assigned him a cadence: Whatever Brett Favre said.

It wasn’t just the words — in this case, Favre’s trademark Green 58, which Favre said he chose because he liked the flow of it — but also the rhythm and sound. If Hasselback played, the coaches told him, the other players needed his cadence to be consistent. Hasselbeck listened to Favre and tried to replicate him, but one day Packers quarterbacks coach Mike McCarthy walked over.

“He’s like: ‘You need to go home and literally practice with a teammate or practice in the mirror,” Hasselbeck recalled, which is exactly what he did.

These days, the cadence can be used to sync up pre-snap motion, confuse defenses with a dummy call or signal another subtle change. But like filler lyrics in a pop song, the cadence is usually less substance and more melody. Consider Cowboys quarterback Dak Prescott, who eschewed Blue 42 for something simpler but still rhythmic: “Here we go!” Or former Vikings quarterback Joshua Dobbs, who prepped for emergency action in 2023 with a quick warmup: He practiced his cadence on the sideline with his new team’s offensive line.

The biggest key these days is consistency.

“You’re trying to give your offensive line the best jump you can get on a defensive line,” Bray says. “If you have the same rhythm in your cadence every time, the O-line gets used to you and they’re able to jump your count.”

As NFL offenses have become more reliant on motion, the rhythm has become the thing. The words or color may not matter, but the pre-snap motion must time up exactly with the syllables, so the cadence still does.

It’s why former NFL QB coach Rich Scangarello once gave a quarterback a recording of every play in the playbook, so he’d know how to say each one at the precise time needed. It’s why Lock, like Hasselbeck, once rehearsed in front of a mirror. And it’s why Hasselbeck, nearly a decade into retirement, can still recite exactly how he uttered his cadence.

Quarterbacks may not understand the long history behind why they’re barking a color and number incessantly. But the act has become a calling card and catch phrase and, with less emphasis on cadences in college, a rite of passage in the pros.

(Illustration: Demetrius Robinson / The Athletic; photos: Maddie Meyer, David Eulitt Cooper Neill, Jonathan Daniel, Will Newton / Getty Images)