It’s a team sport, but there is one skill in volleyball that is all on the individual player. One that is — literally — on the line.

Serving.

It can be momentum building just as easily as momentum killing. It could have been the death of Hawaii’s hopes to defend its Big West title last week when the Rainbow Wahine set a season high with 16 service errors at Long Beach State and, 24 hours later, reset the mark at 17 at Cal State Northridge.

That’s 33 … count ‘em … 33 free points combined given to the 49ers and Matadors. The surprising thing?

“That we ended up winning both,” senior setter-turned-hitter Kendra Koelsch said. “If you look at that number … wow, and we still won.”

The key to pulling out the victories — in four at the Walter Pyramid, in five at the Matadome — was cutting down the errors when it mattered. At the end of each of the matches.

It was particularly true on Saturday in Set 5, when the Wahine had five aces before their first service error, and that came on their first match point at 14-7, and after junior reserve setter Faith Ma’afala had just served two consecutive aces.

The final ratio against the Matadors was acceptable — 16 aces to 17 errors — but continued to confound Hawaii head coach Robyn Ah Mow-Santos.

“I know my team can serve — it’s the skill we work on the most,” she said. “We work on it for an hour and a half every practice. I don’t know what it is when we get into the game.

“We need to work on our mental part of the game, work at being steady, at winning the serve-and-pass game. We want to take the other team out of system with our serve and us stay in system with passing. We do that and we’re good.”

If the Wahine don’t, they have gotten into trouble. It happened on Sept. 30 at UC Riverside, Friday’s opponent.

Hawaii was eight points away from being swept by the Highlanders when it was down 2-0 in sets and 17-16 in Set 3. The Wahine pushed it to a fifth for what would be the first of three straight Saturdays going five, closing it out 15-7.

Three of Hawaii’s first five losses were 3-2. With the win last Saturday the Wahine are now 3-4 when it goes five.

“It seems like we like the endurance game,” junior hitter Casey Castillo said. “But (at Riverside) it should never have gone to five. We weren’t ourselves that night.

“I think things shift being home. We’re motivated to have it done quickly. We want to show them what team we really are.”

“I think at Riverside it was more on our side,” senior defensive specialist Gianna Guinasso said. “It was hitting balls out, the miscommunication.

“We’re comfortable if it goes five. The nerves are good ones, about being excited to play. A lot of other teams are like, ‘Oh, no, we’re going five.’ But I think we’re built for it, we’ve trained hard for it. Of course, I want to see us winning in three, or even four. Mathematically (set differential in tie-breaking scenarios) it’s better.”

After losing to Cal Poly two weeks ago in five, Hawaii (13-6, 7-1) continues to chase the Mustangs (17-2, 7-0) in the standings. While the Wahine are hosting UC Riverside (9-10, 1-6) and Cal State Fullerton (4-17, 0-8), the Mustangs host Long Beach State (6-15, 3-5) and Cal State Northridge (10-9, 4-3).

Friday is the only match of the week for the Highlanders, who are led by Kamehameha-Hawaii product Kaiulani Ahuna (3.28 kills per set), a junior hitter who transferred after two seasons at Eastern Washington.

The Titans were swept at home on Tuesday by Long Beach State, 25-22, 25-19, 25-20, and bring an 11-match losing streak into Saturday’s match.