Here’s why NFL teams are training in virtual reality by John Gaudiosi @FortuneMagazine August 10, 2015, 4:39 PM EDT E-mail Tweet Facebook Linkedin Share icons What do the San Francisco 49ers, Arizona Cardinals, Minnesota Vikings, and Dallas Cowboys have in common? All four NFL teams are using 360-degree virtual reality from startup StriVR Labs to help players and coaches analyze plays on the field. StriVR’s VR technology, designed by former Stanford kicker Derek Belch of StriVR Labs, uses 360-degree high definition video capture of each position on the football field and every play on both offense and defense for each team it works with. Unlike Eon Sports VR’s Sidekiq, which uses 3D video game-style graphics to teach players, StriVR focuses on 360-degree video for a reason. “All of the research coming out of Stanford’s VR Lab is that the human gait is incredibly important in how our brain perceives something,” Belch says. “It’s imperative for the high-speed, fast decision-making athletes to see natural gaits of other players in VR. Even if you’re looking at a good video game, the avatars are not going to move like real people, so your brain will tune out. It will have a cool factor, but not a presence factor there.” Belch wrote his master’s thesis on virtual reality as a training tool while he was an assistant football coach at Stanford. Stanford quarterback Kevin Hogan had the three best games of his career after using the VR technology in 2014. After seeing those types of positive results with the Stanford football team, Belch founded his startup in January 2015 and sold the concept to college football programs at Clemson, Auburn, Arkansas, Dartmouth, and Vanderbilt. This year, Belch took StriVR to the NFL. Once the Cowboys started raving about the technology, additional NFL teams signed on. And Belch expects to add more college and pro teams to his list of clients. The Cowboys, which signed a two-year deal with StriVR, have built a soundproof room in their video department for coaches and players to use the technology. Head coach Jason Garrett says that StriVR allows him to get closer to all 22 players so he can see details like where they have their feet, where their eyes are looking, and hand placement. Ultimately, being closer than the traditional video wideshot allows coaches to coach better. “VR is going to be a tool that is going to be helpful for us as we go forward,” Garrett says. Belch says VR is helping both college and NFL teams safely prepare players for games without requiring them to be on the field where they risk injury, as well as having to deal with intense summer heat. Both college football and the NFL have strict rules and restrictions on how much time can be spent on the field, so virtual reality allows players to simulate being there from the comfort of an air-conditioned room. While Belch believes VR can help every player on the field improve their mental timing and performance, Cowboys quarterback Brandon Wheedon finds StriVR invaluable because it provides him reps that he doesn’t get as a backup. There’s also a rewind option that allows players to rewatch plays again and again. Coaches can even see what the player is seeing and speak to them through the VR headphones. It’s because of this type of personalized instruction that down the line, Belch believes VR may replace film watching completely. StriVR currently runs on the Oculus Rift, but Belch expects the technology to expand to HTC Vive and other VR platforms in the future. Sign up for Data Sheet, Fortune’s daily newsletter about the business of technology.