Through three seasons at Houston Baptist University and a fourth at Western Kentucky, Bailey Zappe’s offensive coordinator peddled a seemingly counterintuitive axiom.

“I don’t believe in perfect play calls,” Zach Kittley, now Texas Tech’s offensive coordinator, told Yahoo Sports. “You’re playing against coaches that are really good. They’re going to give you something you’re not expecting.”

Quarterbacks, Kittley believed, could and should change some calls at the line of scrimmage. So he celebrated when Zappe checked out of a run play to execute a passing touchdown, and also chuckled when Zappe’s understanding of a starter play call — it might as well have been considered just starter, given the quarterback’s freedom to change direction — prompted him to wave off his coordinator mid-signal. Zappe, Kittley understood, already knew what was coming.

And the more coach could empower player to act accordingly, the more Zappe would eventually be ready for the NFL, he believed.

Fast forward to last Sunday, and the fourth-round quarterback considered “undraftable” 14 months ago by some talent evaluators, completed 17 of 21 pass attempts for 188 yards, a touchdown and an interception, generating a 100 passer rating as the New England Patriots won his first NFL start.

A strong run game and shutout defensive performance no doubt helped. But Patriots head coach Bill Belichick didn’t downplay Zappe’s role.

“He was confident out there,” Belichick said after the Patriots’ 29-0 win vs. the Lions. “He does a good job of seeing the game and can come off and identify and articulate what happened, and that’s usually right. What he saw is usually what I saw, or maybe when you look at the film, maybe there’s something that’s a little gray in there that his explanation is actually good. It was the way he saw it.

“He might not have done the right thing, but he saw the game.”

Patriots fans now wait to see how long he’ll continue to start while Mac Jones is out injured. But those close to Zappe have seen this narrative before.

‘Keys to the Lamborghini’

Patriots team owner Robert Kraft found Zappe in the locker room Sunday and summarized well his nearly two games of play. (Zappe came in relief for Brian Hoyer against the Green Bay Packers at Lambeau Field, completing 10 of 15 passes for 99 yards and a touchdown.)

“Great poise,” Kraft said, after embracing the rookie. “You showed it last week, and I wanted to tell you.”

It’s that poise, arguably, that best describes how a zero-star recruit whose first four years of college football were at the FCS level has managed to diagnose a game so early in his NFL career.

Zappe grew steadily at Houston Baptist, improving his gross production and completion percentage each season. In his final two years, he threw 50 touchdowns to 16 interceptions. And on his largest stage, against Texas Tech in 2020, Zappe threw for 567 yards and four touchdowns. HBU, entering the game as 41.5-point underdogs, lost just 35-33.

Scouts and his now-agent Nicole Lynn were impressed with Zappe “slinging” it. Senior Bowl executive director Jim Nagy was more realistic with the draft prospects of the 6-foot-1, 220-pound Zappe.

“There would have been level-of-competition concerns,” Nagy told Yahoo Sports. “He had one nice game vs. Texas Tech, but that’s not a very big sample size. So I think the odds are he would have been an undrafted free agent.”

With his COVID-granted year of eligibility, Zappe transferred to Western Kentucky, where Kittley was then coordinating. The move from FCS to FBS play didn’t faze him, Zappe instead breaking an 18-year-old NCAA passing record with 5,967 yards. His 62 touchdowns in 14 games also set a new NCAA mark, supplanting former LSU and current Cincinnati Bengals quarterback Joe Burrow’s previous record of 60 (in 15 games). And in games against the Big Ten’s Indiana and No. 17 Michigan State, Zappe rose to the occasion. He completed more than 70% of his passes each game, tossing six total touchdowns to no interceptions.

Zappe’s instincts, anticipation and awareness impressed NFL talent evaluators. But Zappe wanted those who considered him a limited college product to know: He wasn’t simply airing it out. He’d freestyle at the line of scrimmage on play calls, also navigating NFL-length verbiage like “shark flip bee buzz pop lakers toss 90 swap” on which Kittley says he threw a 35-yard touchdown pass.

“Coach Kittley gave me, like he said, the keys to the Lamborghini,” Zappe said at the NFL scouting combine in March. “I was able to check in and out of plays whatever I saw fit, whatever I saw the defense was doing and I think how that translates to the NFL is kind of the knowledge-of-the-game part. Being able to read defenses and see what the defense is in pre-snap, I think that will continue to help me throughout my career in the NFL, just recognizing what defenses are doing against us.”

Zappe was asked that day if being a “game manager” was a compliment.

“One-hundred percent,” he said, before adding a now-almost-eerie postscript. “The greatest player of all time is a game manager: Tom Brady.”

Could Bailey Zappe start even when Mac Jones is healthy?

When the Patriots drafted Zappe in the fourth round of the 2022 draft, league voices wondered: Why take a quarterback so high a mere year after drafting Jones out of Alabama in the first round, with the 15th overall selection?

Patriots director of player personnel Matt Groh said what then sounded like coachspeak.

“Yeah, one guy is on the field, but you better have another good one or two or three in the system coming up,” Groh said April 30. “You never know when those guys are needed. And if you’re short at the position, you’re going to be in real trouble.”

Within five months, trouble arrived.

Jones suffered a high ankle sprain Sept. 25 against the Baltimore Ravens, and the backup Hoyer then suffered a concussion Oct. 2 at Green Bay. The third-string Zappe was thrust into action in what was ultimately a 27-24 overtime loss. Then he started against the Detroit Lions, with Belichick and teammates praising how Zappe’s decision-making and execution improved from the prior week.

Jones’ status for this weekend’s game at Cleveland remains in question, with coaches saying he’s working to get back without a timeline. But Zappe’s play has generated a 104.7 net passer rating to Jones’ 76.2. Zappe has thrown two touchdowns with one interception to Jones’ one touchdown with five interceptions.

The sample size is small and uncontrolled. Yet Belichick didn’t proclaim a healthy Jones the unconditional starter Monday when asked.

“I’m not going to get into a lot of hypotheticals on all those different things that might or might not happen,” Belichick told Boston radio station WEEI, lauding Zappe’s handling of man and zone coverage changes. “That’s just, to me, a waste of time. I’m not going to sit around and dream up scenarios and all of that. We’ll take things as they come and go from there.”

He added that Jones “wasn’t active” vs. the Lions so there hasn’t yet been a decision to make.

Zappe, too, is focused on simply taking the developments in stride. He lauded his offensive line, weapons and defense for supporting him. The Patriots still have only a 28.4% chance to make the playoffs, per Football Outsiders, but that increased 7.9% with the win in Zappe's first start.

The defense, the run game and Zappe doing enough was a recipe to beat the Lions, and it could well be again this weekend against the Cleveland Browns.

Regardless, Zappe's demeanor stays even.

“Like I’ve always been told, taking advantage of your opportunity,” he said. “Getting 1 percent better every day.”

Follow Yahoo Sports’ Jori Epstein on Twitter @JoriEpstein