The differences between collegiate men’s and women’s volleyball are few but they are significant. It goes beyond the 71⁄2 inches that determines the height of the net — the men at 7-115⁄8, the women at 7-41⁄8.

Besides the libero being able to serve (yes for women, no for men), the number of substitutions per set varies (15 for women, 12 for men). However, there is a huge difference within that substitution number as spectators at the Hawaii-USC men’s volleyball match witnessed on Jan. 6 at the Stan Sheriff Center.

While a player is allowed to re-enter a set an unlimited amount of times within the allotted 15 substitutions on the women’s side; on the men’s side, a starter may be subbed out and return once, while a sub can only enter and leave the set once.

It was that last difference — a re-entry error — that cost the Trojans late in Set 3 against the Rainbow Warriors. With USC leading 19-18, reserve junior Jon Rivera went back to serve and the Trojans scored off an overpass to extend it to 20-18, forcing a Hawaii timeout.

The problem? Rivera had already played in Set 3, serving three times beginning with the Trojans ahead at 12-8. The computer program caught the error during the timeout — as did both benches. USC tried to put the correct server in but it was too late; the point was reversed, tying it at 19, and Hawaii went on to finish the 25-17, 25-20, 25-22 sweep.

Whether it would have changed the outcome in Set 3 had the error not been discovered will remain up for debate. What is indisputable is how technology has changed the sport for the better.

“You want to get the calls right,” Hawaii coach Charlie Wade said as the No. 3 Warriors prepare for this week’s huge matches with No. 2 UCLA. “It was surprising (on USC’s part). There’s usually someone on the bench keeping track. I do it so I always have it in front of me. With DataVolley (the computer tracking system), there’s more oversight.”

One other thing that Wade — and all the other coaches in the sport — can see is the value of the statistical program. It provides an analysis as to trends, tendencies and set distribution both for opposing players and teams.

Still, the one thing that all the statistical data out there cannot help with is the human element. That will be personified this week in UCLA junior setter Micah Ma’a.

“The thing about Micah is he’s a risky guy,” Hawaii senior libero/hitter Tui Tuileta said of his former Punahou teammate. “He’ll dump it when you least expect it, set the hard sets when you least expect it.

“With him, expect the unexpected.”

Not unexpectedly, the Bruins are coming off a big weekend at home where they won the AVCA Showcase with a four-set victory over No. 9 Penn State and then downed No. 3 Ohio State in five. Friday’s win over the Nittany Lions gave coach John Speraw his 100th at his alma mater and Saturday’s against the Buckeyes was his 300th career overall.

The Warriors are off to their best start since 1996, the season they fell to the Bruins in five for the national championship. Hawaii puts a 25-match home winning streak on the line against UCLA, which it defeated twice in four sets last April in Westwood.

UH also has not dropped a regular-season nonconference match since 2013 (Penn State in five). With the creation of the Big West, the Warriors and Bruins (Mountain Pacific Sports Federation) are no longer in the same league.

“We’re approaching it like another game,” Tuileta said. “I think it’s going to be the fastest offense we’ll face this season.

“We know they’re a really good team and the guys are excited. Biggest difference this year is we’re home. It’s nice to have a home-court advantage.”

Tuileta, an All-American second-teamer at libero last season, has played that position as well as outside hitter and serving specialist this season. He wouldn’t mind serving when at libero.

“You always like the chance to go back and rip it,” he said.