– On Friday morning, the spandex gets squeezed on and the whistles busted out as on-field workouts begin at Lucas Oil Stadium, the home of the NFL’s scouting combine. Millions lounging on their sofas will tune in to watch draft hopefuls zigzag around three orange cones.

In its fourth decade, the combine has become a spectacle, where a record time in the 40-yard dash this year would win somebody their own private island (thanks to Adidas) and any blooper is sure to go viral (Google “Chris Jones wardrobe malfunction” … as long as you aren’t at the office).

But sometime in the early 1980s, one of the combine’s most useful drills, the three-cone drill, was discreetly developed by the late C.O. Brocato, who was a legendary scout for the Houston Oilers/Tennessee Titans.

“C.O. was a guy people respected. He did a lot of things differently,” said Gil Brandt, another scouting pioneer who helped build the early Dallas Cowboys dynasty. “I don’t know [how he got that idea]. Back then, people didn’t share a lot of information like they do now. It was highly secretive.”

Because of that secrecy, Brandt, a human encyclopedia of NFL draft history, is unable to pinpoint the exact year that Brocato came up with the drill. He guesses it was a couple of years after the late Al Davis, who coached and owned the Oakland Raiders, came up with a comparable drill in 1982.

“Al Davis had a similar drill they called the four-square drill,” Brandt recalled this week. “That was one of those things that never caught hold.”

The three-cone drill did. Gradually. It took years to become commonplace. But it is one of the drills NFL talent evaluators will watch closest this week, especially when the running backs and defensive backs are up.

“A guy changing directions, no matter what position he plays, I think is very important,” said the 83-year-old Brandt, who is an analyst for SiriusXM NFL Radio. “If a defensive back runs a 4.5 [in the 40] and about eight [seconds] in the cone drill, he is in all likelihood not going to be a player.”

How it works

The three cones are placed five yards apart in the shape of an L. Exploding off the starting line, a prospect races from the first cone to the second and back. He then sprints around the second cone, loops around the third then bends back around the second cone on the way to the finish line.

No, the drill isn’t technically football. But it’s not too different from a pass rusher bending around a tackle or a pass-catcher turning upfield.

The fastest three-cone time recorded at the combine in the past decade belonged to Jeffrey Maehl, who clocked in at 6.42 seconds in 2011 but went on to catch only nine passes in his brief NFL career.

Eleven players since 2007 have been timed at 6.50 seconds or fewer in the drill.

“Now, what is a little bit misleading is that they practice it,” Brandt lamented. “When it was relatively new, nobody practiced it. Now all these guys are going to fitness gurus. They go there and they practice running it.”

One of the top gurus is Pete Bommarito, the owner of Florida-based Bommarito Performance Systems. Dozens of NFL players, including Vikings players such as Stefon Diggs and Kyle Rudolph, have flocked to him to begin training for the combine once their college careers ended.

Bommarito, who has two dozen clients at the combine this week, used phrases such as “joint alignment” and “horizontal power” as he explained how he gets them ready to attack the three-cone drill in Indianapolis.

“People think it’s an agility test. It’s more power. The first five [yards], the second five transitioning into the third five where you round the corner, that’s power. You’re not running. You’re legitimately doing a jump,” the muscle-bound trainer explained. “After that it becomes an agility drill.”

Drills for on and off the field

Bommarito feels that everything they do at his two Florida facilities helps his clients ace physical tests like the three-cone drill. But he estimated that they spend 24 hours a week focusing specifically on the on-field combine drills, which include the 40-yard dash, the broad jump and vertical jump.

His pre-draft training program also includes football skills training with coaches, time in the film room and combine interview prep to get ready for the 15-minute sessions with teams that are similar to speed dating.

Trainers nationwide such as Bommarito charge thousands to participate in their combine prep programs. But he grins when it is pointed out that his speed and agility training have made past clients millions of dollars.

Despite prospects learning to master these drills ahead of time, NFL teams still value the three-cone “a lot,” Brandt said. That includes the Vikings.

Harrison Smith was the top-performing safety in the drill at the 2012 combine, and Matt Kalil was second among offensive tackles. Anthony Barr was one of the top linebackers in 2014. And the three-cone was one of a few drills running back Jerick McKinnon crushed that same year.

“I think what we’re finding out now as we evolve with the analytics is what tests are the most important for each position,” General Manager Rick Spielman said here Wednesday morning. “The three-cone may be important for one position but not as important for another.”

Which positions would those be? Of course, Spielman wasn’t about to offer up that top-secret piece of intel.

C.O. Brocato would be proud.