Helton said he was going to use it to read minds.
"Before you put this on," Helton said, "I can turn this thing anywhere and see where you're looking."
To demonstrate, he rotated the helmet from left to right. On a television monitor next to him, a view of USC's practice field panned in sync, left to right.
The helmet is USC's latest edge: a virtual-reality set that allows quarterbacks to enter each other's eyes and take repetitions virtually, and for coaches to follow along, seeing exactly what the quarterback sees.
At each practice this season, a student trails the quarterbacks holding a long boom topped with cameras pointing forward and back. The student holds the boom a few feet above the quarterback's head. Within an hour after practice, the quarterbacks can don the headset (or watch on an iPad), cue up each play and look around in 360 degrees as if they were back out on the field.
The Trojans have joined a growing number of teams chasing a technological advantage.
On Monday, USC provided a glimpse at how its quarterbacks use the system to steal precious practice hours on the virtual field.
Inside the helmet, a glance down revealed the top of a helmet shining in the sun.
"All right now this is on Sam, OK?" Helton said.
Quarterback Sam Darnold's hands were outstretched for the snap. Straight ahead were USC's linemen. Through headphones, coaches barked instructions. It was like stepping into Darnold's head — or that of some organism floating right above him.
Look to your left, Helton said. A turn of the head showed Deontay Burnett in the slot. Cornerback Ajene Harris lined up opposite Burnett, mirroring him — a bad sign for that route.
"So right now Sam should say, 'No, I don't have it,'" Helton said.
The clip rolled forward. The ball was snapped. Darnold tried Burnett anyway. Harris jumped the pass and nearly intercepted it.
What was he thinking, Helton wanted to know. After practice, Helton ran the play back. He could follow Darnold's head, look at what Darnold looked at: namely, Burnett and Burnett only.
"Sam being Sam, he thinks he can fit everything in there," Helton said.
In the film room, Darnold knew his error immediately.
Unlike basketball or baseball players, football players earn only marginal gains training on the field alone. The best learning comes in full team drills. But that takes time and people and carries an injury risk.
So Stanford coach David Shaw, an early investor in STRIVR, which was founded by a former Stanford player and graduate assistant named Derek Belch, started his quarterbacks on virtual reality in 2014 to trick their minds into thinking they were seeing real action.
"In the middle of a game, the plays about to start, and he says, 'I've been here before. I know what's going to happen. I've seen this before,''" Shaw said of his quarterbacks at last year's Pac-12 media days. "Boom. Change the protection. Touchdown pass."
Bill McCarthy, the football product manager for XOS, said teams have experimented with deploying cameras at different positions such as linebackers or even the personal protector on punt drills.
USC coach Clay Helton said the running backs have found the training particularly useful. Last week, he was excited about experimenting with the linebackers.
"We tried it," said Eric Espinoza, USC's director of football video operations. "It just didn't give the look that he wanted, and where we were going to place [the cameraman], the defensive coaches were worried about safeties coming up from behind and hitting him."
Espinoza and another video staffer, Daniel Dmytrisin, crunch all of USC's practice video. Coaches and players hoard, consume and obsess film as if it were legal tender. Film shows which player can win a starting job. It shows which opponent has a tell. It shows what opposing teams will do to break opponents down.
USC records from towers high above its end zones, zoomed out to fit all 22 players. Tyson Helton said he still uses this tape 80% of the time. But it leaves important gaps.
"A lot of times when you coach in the film room and you're looking at the video from the angle up top," Helton said, "it doesn't tell the true story of what [the quarterback] saw."
For players, standard game film is like a good textbook. It's the foundation. But sometimes what they need is a lab. This is especially true for backups.
"Sam uses it some, but because he's getting a lot of reps and he's a little more experienced player, he already knows what he's done wrong," Helton said. "But the beauty of it is the young players, the young quarterbacks, because it allows them to get the closest thing to a live rep as possible."
Jack Sears, USC's freshman quarterback, uses the system more than anyone.
"Jack's a gym rat," Helton said. "Jack lives at the office. I mean, literally you have to kick him out, like, 'Jack go home, man.' Because he enjoys the process. He enjoys it. Right now he doesn't know anything, and he knows he doesn't know anything. So he's trying like hell to get caught up."
Helton cued up a play from a recent practice. The play gave Sears an easy read to either side.
"You'll watch Jack's eyes right here," Helton said. "Watch him. He goes left with his eyes. He goes right with his eyes. And then back late. You kind of see his head moving a little bit."
With the camera angled down from a few feet over Sears' head, it's clear that both options are open, but his helmet swivels as if he were shaking off a 3-2 curveball. Sears' hesitation let a blitzing linebacker through, so he took off and ran.
To correct these misreads, Sears spends about 20 hours a week watching film on his own, a majority of it in virtual reality.
It is a powerful advantage. The NCAA allows coaches to spend 20 hours a week with players on football-related activities. But Darnold alone takes about half of the repetitions during practice. During the season, his workload bumps to about 75% of repetitions.
As Helton left the film room Monday, Sears walked in, holding a skateboard.
"We were just talking about you," Helton said.
Real practice would begin in a few hours. But before it began, Sears needed time alone, to practice.