Super Bowl prop bets have taken a life of their own in recent years, but who is in charge of coming up with some of the craziest ones? Doug Kezirian takes a closer look. (4:47)

In a man cave 25 miles west of the glitz and glamour of the Las Vegas strip on a Tuesday, three oddsmakers are gathered around a brown leather sectional couch. Laptops, stacks of box scores and legal-sized packets of betting odds are strewn about. Above the oddsmakers' heads is a framed Vince Lombardi picture with the quote: "Winning isn't everything. Making the effort to win is."

A wide-ranging discussion breaks out over Los Angeles Rams running back Todd Gurley II. The fantasy football stalwart led the NFL in touchdowns and was mentioned in some MVP conversations. However, after 115 rushing yards in the team's playoff opener, Gurley had only four carries in the conference title game, battling a knee injury and the emergence of C.J. Anderson.

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One oddsmaker presents an over/under of 73.5 rushing yards for Gurley in Super Bowl LIII, while the others suggest 59.5 and 60.5. "It was just weird [in the NFC Championship Game]. Gurley never left the field and was on the bike for a little bit. They just wouldn't put him in," one says.

"If we put up a number that's too low and the sharps don't get involved, then you're going to get only public on the over," another oddsmaker notes.

"So if we miss here, we want to miss on the high side," the third oddsmaker adds.

Eventually, they settle on 68.5 rushing yards as the SuperBook's opening number. Within a few hours on Thursday night, sharp bettors will have bet the number down to 63.5.

This is the annual tradition for the team of oddsmakers at the Westgate Las Vegas SuperBook who put out nearly 450 prop bets on Super Bowl LIII (and over 1,000 ways to bet the game) that will influence the global betting market on the biggest gambling day of the year.

In 1986, Chicago Bears head coach Mike Ditka made a call that will forever go down in sports betting lore. With Super Bowl XX already decided in the second half, 300-pound defensive lineman William "Refrigerator" Perry scored a rushing touchdown in Chicago's 46-10 blowout win against the New England Patriots.

Some Vegas sportsbooks reportedly opened the betting that Perry would score a TD at 50-1 odds, even though he had scored three times during that regular season. It was one of only a handful of prop bets offered at the time.

"We put it up at 20-1, thinking there's no way that he's going to score. Just not gonna happen," Sunset Station sportsbook director Chuck Esposito told ESPN, reflecting on booking the now infamous bet in his Caesars Palace days. "So we start seeing the odds lower and lower and lower, and now it's 2-1. If he scores, we're looking at possibly a six-figure loss on a fun prop, which was pretty much unheard of in those days."

The short-term loss produced an enormous long-term win for the city. National media outlets picked up the story and sports fans grew increasingly excited about the variety of ways to bet the game. Since then, prop bets have taken on a life of their own and become part of the fabric of the Super Bowl.

William Perry scoring a TD in Super Bowl XX helped to launch the popularity of prop bets. AP Photo/Amy Sancetta

Prop bets currently represent more than 50 percent of the overall Super Bowl betting action. Last year, Nevada Gaming registered a record $158.5 million in betting handle for the Super Bowl, with over $75 million on prop bets alone. Seven additional states now offer legalized sports betting, meaning the legal handle on Super Bowl LIII could double last year's -- with potentially billions of dollars more bet illegally with bookies and offshore markets.

And no sportsbook in the nation offers more props than the SuperBook.

There are over 63 combined years of bookmaking expertise gathered on that sectional couch.

Ed Salmons, vice president of oddsmaking and risk management at the SuperBook, is widely considered one of the sharpest minds in the business. He has final say on every single betting line offered by the SuperBook and has declined offers from competing sportsbooks over the years. He teamed up with current SuperBook executive vice president of race and sports operations Jay Kornegay in the early 1990s at the Imperial Palace, and together they've relocated and added team members.

Jeff Sherman (also a VP of oddsmaking and risk management) stumbled upon a career path he did not originally envision. After graduating from UC Santa Barbara, the Los Angeles native moved to Las Vegas for his MBA. Following completion in 1997, he opted for the hospitality industry, but the sportsbook was an afterthought. Since then, the 47-year-old has learned the craft while specializing in betting odds for soccer, golf and the NBA.

Randy Blum didn't know he wanted to be in the oddsmaking business, but he did know he wanted out of his desk job in New York City. And ironically, he knew the odds were against him, given the bad timing of his relocation decision. During the 2008 financial crisis, he headed to Vegas with the full support of his family and friends.

The 40-year-old began as a teller and then subsequently climbed the ranks. Salmons and Sherman are among those who helped show him the ropes, and Blum also references the first time he "made a lot of bad numbers" as when everything truly clicked.

Each oddsmaker is tasked with creating his own betting lines ahead of meeting at Salmons' house on Tuesday. Given their qualifications and skill set, unsurprisingly they all individually produce similar figures. However, every single prop mandates thorough discussion and analysis, as they all understand the significance of any adjustment and how it could impact the sportsbook's net result. "It's a little bit of a challenge because you have these guys like Tom Brady, who's getting older. So even though you have information to go on from the past, you can't just use the same numbers. You have to make the proper adjustments," Blum said. "I take pride in what I do and I know all the guys I work with feel the same."

"Pressure is only what you put on yourself," Salmons told ESPN. "Ultimately, this is a great job to have and I'm honored to be able to do it with such great co-workers and we try to make it as fun as possible. It's hard to have fun when you're doing it for 16 hours, but we just make the best of it."

Playing a large role in the day's sense of normalcy is Salmons' wife of 30 years, Lynda, who cooks lunch for everyone -- including the ESPN production crew. As the team enjoys brats at the kitchen island, her desire to drive conventional conversation heightens the familial interaction.

Lynda also has embraced the calling, ever since she and Ed relocated from New Jersey in 1991. She recognizes that sports don't take any days off, and their life includes a television and desktop computer on the kitchen counter. "Eddy always has to have WiFi and access to his things," she jokes. Even last February, while the couple vacationed on a cruise, Ed felt obligated to text oddsmaking directions after the Cleveland Cavaliers completed a three-team trade to bolster LeBron James' supporting cast."

Their 14-year-old rescue dachshund, Gabbie, provides well-received levity. Upon new guests' arrival, Gabbie barks until every person walks outside to allow her to show off what she clearly deems a most remarkable invention: bubbles in the hot tub and splashes of water to nibble.

"She won't stop until we all go outside," Linda sheepishly shares while also appreciating the humor of such a simple act in a city full of Cirque du Soleil shows.

"She has to do that when new people come to the house. That's her thing," Ed Salmons said. "The guy that comes to spray for bugs, she has to do the bubbles for him. I mean, it's everyone."

Gabbie's routine fittingly mirrors the entire scene. The houseguests change each year, as do the Super Bowl players. But in the end, the props meeting is a regular duty that comes with the territory.

"Each year there's a different storyline in sports. I know last year when we were doing the props, the Vegas Golden Knights were in their first year and we incorporated them in a lot of props," Salmons said. "This year, James Harden's been scoring 40 points the last month per game so there's always something that brings sports to light where you get new ideas."

"It's for the public. Everyone likes it," Sherman says, while also sharing he was in charge of bringing the Red Bull. "Everyone gets involved in the game another way than just betting the game itself, so we try to offer as many different wagering options as we can. It's a challenge for us."

After two long days of deliberation, numbers for the props are agreed upon and are ready for Vegas' finest bettors to take aim.

With the grunt work over and all the props manually entered into the computer system, the SuperBook gets to bask in the palpable buzz of a triumphant evening. At 7 p.m. PT on Thursday, 10 days before kickoff of Super Bowl LIII, the two-story-high betting board lights up with the full menu of proposition bets. It might not be Rockefeller Center at Christmastime, but the scene does resonate for those with this particular affinity.

"The late 90s, back then, there might be two dozen guys showing up," professional bettor and opening-night regular Frank Betti told ESPN. "It's like a movie premiere now. There are hundreds of guys, cameras and everything. So it's grown a lot in 20 years."

In attendance are media members, locals, and professional bettors -- a who's who of gambling circles to celebrate the unofficial launch of Super Bowl LIII betting.

While it's a congenial atmosphere, don't be fooled by the smiles, handshakes and hugs. This is serious business for both oddsmakers and bettors. It begins with the rules -- shades of the Soup Nazi of "Seinfeld" fame.

Each bettor is allowed a maximum of two wagers per visit to the betting window. They can then return to the back of the line to repeat the process as many times as they want over the next three hours. All bets must be made in person, and wagering on the smartphone app is disabled until the next day.

Over the next three hours, the Westgate takes in over $400,000 in bets, according to Salmons. The demographics have also expanded and include women and bettors of all ages, albeit mostly males.

"Sports betting is actually a market. It's actually not really you against the casino as much as it is you against the other people wagering, because that's where the line moves. So, the pros recognize opportunities where the line moves too far in one way," professional gambler Anthony Curtis says.

There were a wide variety of characters at Thursday night's Super Bowl LIII prop bet unveiling. Doug Kezirian

This is why the SuperBook team grinds for two full days, combing every number and statistical possibility. They aren't concerned with the average fan's random wager -- and they're not about to repeat the same mistake from 1986. Rather, they are solely focused on the professional bettors, who are armed with pockets or backpacks of cash, their own research and advanced computer models -- ready to pounce on what they perceive as advantaged odds.

The level of sophistication has certainly grown. The collection of intelligence and expertise is overwhelming. In his past life, one bettor used to work at the Chicago Mercantile Exchange. Another is an Ivy League graduate with an economics degree. Another is a son of a former bookie. The common thread is that they all have experience with numbers and understand their significance.

Allowing each bettor only two wagers per window visit protects the house from an isolated onslaught of action and gives oddsmakers sufficient time to adjust their betting lines.

"They're the smartest guys in the business that are doing this. If you have a bad line, they'll show you [with their wagers]," Salmons said. "There are some that are even better than others and you get that small circle. They're the guys that you really want to trust as far as your number."

This is only the first night. Between now and kickoff, the pro bettors will canvas all Las Vegas properties to optimize their earning potential, while also utilizing the apps. Some will even travel to the seven other legalized states or team up with partners to cover those regions.

"I've heard guys easily, easily making six figures and I don't mean just $100,000. I mean above the $100,000, $200,000 to $300,000 range," Curtis said.

While pro bettors are consumed with this circus for two full weeks, recreational bettors casually partake in the Super Bowl betting experience without a clue as to the financial gymnastics that have transpired behind the scenes. Yet, both sides share the exact same outlook on what's quickly becoming an American pastime.

"The one negative about it is it only happens once a year," Betti said.