Mike Pereira joined Fox Sports in 2010, shortly after retiring from the NFL, and immediately established the value of the then-new role of television rules analyst.
But it would have been difficult at the time to envision how essential the job would become by 2019.
"The way the NFL rules are these days, I almost can't even imagine you could operate your No. 1 show without having someone up there immediately available," said Jim Nantz, CBS' lead play-by-play man.
Said CBS producer Jim Rikhoff: "I think it's a necessity in this day and age."
That is why Nantz and analyst Tony Romo will have their rules security blanket, Gene Steratore, beside them on Sunday for Super Bowl LIII, after a conference championship day on which Pereira, on Fox, and Steratore found themselves busy.
Steratore worked last year's Super Bowl as a referee, then retired after 35 years as a football and basketball official. He told The Associated Press he might be more nervous for this year's big game than he was last year.
"It's good, nervous energy because there's the lack of 35 years of experience (in television)," he said.
CBS tried its version of the Pereira/Fox model with retired referee Mike Carey in 2014 and 2015, but he was dropped after two seasons amid largely negative reviews.
Steratore has fared better, in part because of lessons learned from the past, including this: Take your time before predicting an outcome.
"It's not a game show where you're hitting the button to get the fastest answer to get the right answer," Rikhoff said on a conference call with reporters to promote CBS' coverage of the Super Bowl.
Rikhoff encourages Steratore to view every available replay angle before signaling that he is ready to go on the air.
"That's the key _ not rush the situation," Rikhoff said. "And also, honestly the way that things work now, we go to a commercial when there's a review or challenge ... which gives him a little more time to kind of digest all the information and form an opinion, maybe even collaborate with someone else."
Steratore worked from CBS' Manhattan studios in the regular season _ other than on Thanksgiving _ but has joined Nantz and Romo in person during the playoffs.
"Gene's a natural," Rikhoff said. "He knows the game, obviously, unbelievably well. He's calm ... A lot like Tony, he's kind of a natural, telegenic."
Said Nantz: "He's fantastic ... He's got a lot of natural ability to articulate what we need to hear in a short window. And there's no hesitation ... I was blown away with how good he was (during the AFC Championship Game)."
While the most talked-about call of championship Sunday was a missed passed interference flag that helped the Rams defeat the Saints, the Patriots-Chiefs game also featured key decisions, several after close-call video reviews.
Rikhoff said there was "about a 15-minute period where it seems like it's the 'Gene Steratore Show.' He had three really, really tough calls. And I thought he did great, handled them all well."
The biggest call might have been the overturn of an apparent muffed punt by the Patriots' Julian Edelman. After a review, it was ruled the ball did not touch his outstretched hands, negating the muff.
For decades, NFL officials privately bristled at announcers misinterpreting rules. Pereira, Steratore and other rules analysts occasionally rankle former colleagues, too, but at least they know of what they speak.
Rikhoff said the current officials probably are the best the NFL ever has had; they just have a faster game than ever to regulate and are under more scrutiny than ever. Rules analysts are there to cut through the noise.
"It's really a complicated game, and it's a fast-moving game," Rikhoff said. "With the combination of those two things, it's imperative to have an official up in your booth."
Steratore told the AP that he tries to keep in mind how difficult the officials' jobs are.
"What I hope to always remember is how hard and fast this game is when you get between the lines," he said. "You probably are never going to work a perfect game ... The game gets harder every year.
"We dwell on the major mistakes made year in and year out, but I don't know if this year was worse than years past."
