In the American soccer habitat, the college version of the sport is a strange bird.

The clock runs down, not up, and the scoreboard, not the referee, is the official timekeeper. A reentry rule allows players to leave and return. Substitutions are unlimited. A deadlocked regular season match does not end in a draw after 90 minutes, instead going to 20 minutes of sudden-death overtime but no penalty kicks.

For most players with unrealistic sights on pro careers, the NCAA’s quirky guidelines have little bearing. But for top prospects and the coaches who are trying to improve the quality of the college game, non-uniformity to the sport’s global standards is a hindrance.

With the NCAA slow to embrace change, the U.S. Soccer Federation tried something new this year by introducing the Spring College Program. In it, six high-end men’s programs — five from the ACC, plus Georgetown — played friendlies against one another using many of soccer’s core principles.

Each team played five matches: two home, two away and one this past Saturday when all sides descended on Wake Forest for a triple-header. North Carolina won the championship with a perfect record, culminating with a 1-0 victory over Duke. Virginia and Georgetown each had 2-3-0 records. Clemson was the other participant.

The USSF augmented the program with video and match analysis and by assigning national team scouts. On Friday, the six coaches met with USSF youth technical director Tab Ramos and other officials to discuss benefits and drawbacks.

The women did not have a tournament but, after hearing about the experiment, Clemson and Florida volunteered during a youth showcase this month in Greensboro, N.C. The federation is hoping to continue the program next spring, said Jared Micklos, director of the USSF’s Development Academy, which focuses on youth initiatives.

Such tests are not possible during the official fall season, but in the spring, when teams practice, play exhibitions and tour overseas, there is flexibility.

“It’s something we’ve talked about internally and externally over the last couple of years,” Micklos said. “And a lot of people have come to us to talk about the college game.”

The USSF has no say in NCAA matters but does have a stake in college-aged players. The spring experiment addressed development in Zone 3, which Micklos describes as “the difficult age between youth and pro. It’s a tough transition. We’re looking at that as a critical gap period, and the colleges are a prime opportunity to address it.”

Coaches in the spring program were limited to 18 eligible players and, using rules closer to international friendlies than formal club matches, could make seven substitutions instead of three. To avoid constant disruptions, they had to make those subs at three moments of their choosing. (Halftime did not count as a moment.)

Aligned with FIFA’s Laws of the Game, the referee kept the clock and, when necessary, added stoppage time. Unlike official NCAA games, the scoreboard clock was unofficial, so it did not stop and the public-address announcer did not count down the last 10 seconds. Because of the tournament format, overtime and penalty kicks were available, though, as it turned out, not necessary.

Virginia Coach George Gelnovatch said the reduction in stoppages for substitutions was “wonderful,” allowing better game flow and more goals. (The five matches involving the Cavaliers featured 18 goals, while Georgetown games had 20.)

Fewer disruptions were not the only reason for increased scoring: Without the ability to insert unlimited fresh players, coaches had to rely on their regulars fighting through — and at times succumbing to — fatigue.

With no reentry, players needed to break away from what Georgetown Coach Brian Wiese called the “30-minute shift mentality.” Often in college games, coaches rest players for the last portion of the first half and reinsert them after halftime. There was also a learning curve for coaches who have spent the bulk of their careers following the NCAA’s byzantine rules.

With international guidelines, the matches seemed more authentic.

Players from abroad, Gelnovatch said, “are scratching their head when they first get to college, wondering, ‘What the …?’ For my guys, 100 percent, it’s a bigger, more proper feel.”

Weise said following traditional rules is “on everyone’s mind. It’s more like what the game should be.”

The NCAA is starting to come around. Last month, the rules committee recommended making referees the official timekeepers and to follow international guidelines of counting up, not down. Such proposals must be approved by an oversight panel, which is scheduled to discuss proposed changes this week.

“NCAA rules need to change,” Wiese said. “I don’t know if it needs to go to the extremes, but I think there is a happy medium.”