Back in May 2017, Forrest Griffin and James Kimball waited as the doors opened at the UFC Performance Institute. They were worried nobody would show.

The UFC Hall of Famer and longtime promotion employee had gotten some funny looks shuttling between the main office in Las Vegas and the 30,000-square foot facility then under construction. Colleagues didn’t quite understand what the place was going to be. “Are you guys building a gym?” they asked. “That ain’t gonna work.”

Two years later, nobody’s worried about attendance. Things are working – maybe too well.

The PI’s initial goal, Kimball told MMA Junkie, was to work with 60 percent of the roster by the end of the first year. It beat that by 10 percent. At the end of Year Two, it was up to 80 percent, or 450 of the approximately 550 fighters under contract.

On a monthly basis, the facility now supports approximately 175 fighters, or one-third of the UFC roster, Kimball told MMA Junkie. The goal is to get that up to one-half by the five-year mark.

“What we’ve provided the market … is new, unique – it’s specialized,” Kimball said. “As robust as we package it, if you’re a combat athlete, let alone a UFC athlete, you don’t have access to this type of comprehensive support anywhere in the world.”

Two years ago, there were 12 athletes on the UFC roster living in Las Vegas. Today, there are more than 30. Is the PI responsible for that? It’s hard to prove. Some probably came for the sun and the gambling. Others, like recent UFC flyweight title challenger Jessica Eye, uprooted their lives to have access.

“I think a lot of people have no idea what is offered to us here, and all the extra things we can utilize,” she said. “I’m 32. I’m not a young fighter any more. I feel like my knowledge is there and (I’m) in the best possible position I could be in for a title fight. But my body needs better recovery, and this is the place to do it.”

It helps that everything is free (unless you’re a visiting pro athlete; Bellator fighters, you need a UFC chaperone). State-of-the-art training equipment, fancy diagnostic machines, physical therapists, food and many other perks are all gratis. All a fighter has to do is make it out to Vegas and pay for a hotel. UFC stars Claudia Gadelha, Joanne Calderwood and Francis Ngannou are among those who’ve recently made the trip to finish training camps.

“You get access to these high, high-level people,” UFC middleweight Brad Tavares said.

The PI also engages with a “direct intervention,” in which a fighter who’s injured or in the throes of a tough weight cut gets flown out for a pit stop of rehab care. Kimball puts the PI’s “save rate” – or the number of fights not canceled “that we can directly correlate” – at 25 fights, or about one per month since the May 2017 opening.

Not all of those flown out on the company dime were pay-per-view headliners. A few, however, might have saved the UFC millions of dollars. And while Kimball claims the PI isn’t profit driven, saving a pay-per-view headliner rarely is bad for business.

Kimball said the PI has spent around $14 million on equipment and expertise to help fighters get the best out of their bodies. Healthy fighters fight longer, and the promotion has a more stable roster to build fight cards.

Along the way, the institute might be changing wholesale the way modern MMA fighters prepare. This past year, a “coaches summit” served as an educational walkthrough for 60 of the biggest MMA camps around the country, some famous for a training approach that could be described as recuperation-hostile.

The PI doesn’t want to get in the middle of a fighter’s ever-expanding camp, Kimball said. Because many fighters can’t afford to fly to Las Vegas on a whim or stay once they get there, 50 percent of the staff’s work is done online via Skype, WhatsApp and FaceTime, checking up on plans set in motion with an in-person visit. Coaches are always a part of the process, he said.

“We knew we could not open up this facility and say it’s our way or the highway,” Kimball said. “That was not going to fly in this industry. We knew the community. That was never going to work. Our mission was to work with the athlete and the coaches. We don’t get involved in MMA strategy. What we’re doing is very specific to performance sports services.”

UFC welterweight Max Griffin said the PI’s staff sets goals based on performance metrics measured at the facility.

“They like to get you in there and work on these strength tests, so they can do these diagnostics,” he told MMA Junkie. “Basically, you get an app called ‘Digital Coaching,’ and it connects with everyone at the PI, all the teams.

“Basically, they plug in your workouts for the day. You check them off, and your strength coach gets it directly. And also, when you’re done working out, you can say your hands or your shoulders are sore. So maybe the next day, they’ll make adjustments to not do shoulders. We’ve found a lot of success in that.”

Onsite at half of the UFC’s yearly events are physical therapists and nutritionists on staff at the PI who do adjustments and dole out last-minute advice. A meal-plan sponsorship with Trifecta means that between 14 and 18 athletes per card are fed during fight week.

“Everything’s more streamlined,” Griffin said. “We work together. It’s not like one guy is telling me to do something and the other is telling me to do the opposite. It’s now to the point where (a PI staffer) has been on the phone (with my chiropractor) for treatment. I think if you open your mouth and you bridge those gates, it works great.”

Because everything in a major corporation must be scalable, the UFC plans to reproduce the Las Vegas PI in as many as six cities globally, beginning with a 90,000-square foot Shanghai facility, which will serve as a talent incubator as well as rehab destination.

“If the number of Chinese athletes on roster hasn’t doubled or tripled, we haven’t achieved what we set out to do,” Kimball said.

In the next two years, the Las Vegas PI aims to support half the roster. It’s already doubled its staff to 16 from the initial eight and hopes to service every event on the schedule in the near future.

Griffin, who hails from Northern California, considers the facility another training home. He makes monthly visits to check his VO2 max and other conditioning metrics. And eat – gratis.

“I want to see where my numbers are,” he said. “I like to reevaluate after every fight so we can build on what we need to work on for the next one.”

For more on the UFC’s upcoming schedule, check out the UFC Rumors section of the site.