Tim Jensen had every reason to be nervous, but the poise of Jennifer Bonilla allowed him to remain confident.

At the most crucial moment of the 18-under open division final at the USA Volleyball Girls' Junior National Championships in July, it was the 5-foot-9 Bonilla -- a Reseda resident and Marymount graduate -- who upstaged 6-2 Washington-bound outside hitter Krista Van Sant, the nation's top high school recruit this year at Redlands East Valley.

With Jensen's Sports Shack team tied 23-23 with Rancho Valley in the second game of the best-of-3 championship match, Van Sant hit around the block for what appeared to be the go-ahead point. But Bonilla, now starting as a true freshman libero for No. 9 Illinois, relied on Jensen's scouting report to cover the open area, make a crucial pass, which led to Lakewood's Jazmine Orozco giving Sports Shack a match point en route to a 25-22, 25-23 victory.

"She saw it coming, scooped it up and we set the outside and scored," said Jensen, also a women's volleyball assistant at Pepperdine. "I talked to three coaches afterward who said that was the biggest moment in the match. That was the play that turned the tide."

Bonilla, a member of the U.S. junior national team, is one of many reasons why the libero -- a defensive specialist identified by wearing a different color jersey than her teammates -- has gone from an overlooked and underappreciated position when it was first introduced internationally

"Anybody who knows volleyball knows it's a premier position," Jensen said. "When we sit down (at Pepperdine) and start identifying needs for our next recruiting class, we're always looking at a big left-side hitter, a setter and a libero. You want to have those positions lined up every year because you have to have all three to win."

So, it's no surprise that four of the area's top high school teams this fall have all relied heavily on the efforts of senior liberos to not only capture league championships, but remain alive in the postseason.

Granada Hills' Marissa Boyd, Harvard-Westlake's Anne Cohen, La Canada's Eirene Kim and Valencia's Brooke Dawson have continued an impressive tradition of talented local liberos since the position became part of the high school game in 2005, following Flintridge Sacred Heart graduate Jenna Orlandini -- starting as a redshirt freshman at No. 11 Washington -- and Westlake alumnae Cathy Quilico, a senior defensive specialist at No. 8 Penn State, a three-time national champion.

"It's exciting that people are starting to realize the play of the libero and defensive specialist and understand how important they are in building a team," said Boyd, a Cal State Northridge signee.

"If you don't have the pass, then you don't have the execution, which means you don't get the points. The game basically comes down to serve and receive and without those two components, you're not going to be successful."

The elite liberos at any level, especially high school, combine a strong skill set with impressive instincts. They possess the reaction time of a soccer goalkeeper, the footwork of a middle infielder, the touch of a gifted tennis player and the improvisational skills of a point guard.

"As the match goes on, you get better at scouting the hitter's tendencies and that gives you a better read," Dawson said. "But a lot of times, you just have to rely on your instincts to make a play."

And whatever they lack in height or physical presence, liberos often make up for by outsmarting their opponent.

"The best thing I've ever learned is how to read a hitter and I'm always trying to outthink them," said Kim, who has attended several USA Volleyball High Performance camps. "The libero is such an underappreciated position, but you are the leader of the defense. You can't just throw anyone in there, you need someone who can serve, who can pass, who can take charge. I feel responsible for getting our setter the ball."

Boyd has developed into a talented libero for reigning City Section Div. I champion Granada Hills after beginning her career at Chaminade. When she transferred to Granada Hills last season, the 5-6 Boyd used her knowledge from previously being a hitter to better prepare herself to defend against opposing attackers.

The result has been a return trip to the semifinals for the Highlanders, with Boyd continuing to play a significant role as a dominant back-row player.

"If I remained a hitter, I don't think I would have had the drive I do now to be a better passer," Boyd said. "We're all leaders in our own way. I'm the leader in the back row."

Boyd is one of 17 seniors on Granada Hills' roster and Cohen is among a group of 11 at Harvard-Westlake, while the 5-9 Dawson and 5-5 Kim are both surrounded by several underclassmen in their lineups. In addition to their physical responsibilities on the court, their leadership has proven to be invaluable, especially in the postseason.

"Our team is so young, I really have to make sure I step up and handle the ball. I'm the quarterback of the defense and I have to tell them what they need to do," Dawson said. "The importance of the libero is so underestimated, but it's such a fun position because you're always involved. The hitters are going to get their attention when they put the ball away, but I get my glory from digging (hitters) and making awesome defensive plays to help our team win."

Aside from the setter, the libero possesses the most responsibility on the court, not only informing teammates how to position their block or defend against opposing hitters, but covering the majority of the back row on serve-receive and when the ball is in play, in addition to being part of the service rotation.

The only contribution the libero doesn't provide is rotating into the front row, but that suits the 5-3 Cohen -- a Johns Hopkins commit -- just fine, because her impact on the match's final outcome could be just as profound as any of Harvard-Westlake's front-row players.

"What we do is so important because most of the time we're the one that makes first contact on our side, so we can determine the fate of the play. The better pass we make, the more consistent we are, the more opportunities (our hitters) are going to get," Cohen said. "I think there's an innate quality you need to have to be good at the position and it's my job to make sure everybody is on the same page."

Much like a relief pitcher, it's a job that requires a lot of confidence and a short-term memory. Justified or not, if the defense is struggling, the responsibility falls on the shoulders of the libero to help a team regain its rhythm.

"Since I'm the only senior that plays, I'd rather (La Canada coach Brock Turner) yell at me than them. I'm training two defensive specialists, so I have to take that fall," Kim said. "I had to really step out of my shell when I became a libero ... I feel like the mother of the team. I have to provide moral support."

With specific camps being conducted across the country and recognition at international tournaments for the top player at the once unheralded position, the libero has become a major position of emphasis for local programs.

Along with Boyd, Cohen, Dawson and Kim, West Ranch's Shelby Kunz, La Reina's Christina Zins, Oaks Christian's Lauren Peddicord, Notre Dame's Jacqueline Lowe, Chaminade's Alex Kruize, Saugus' Maegan Wasserman and Birmingham's Jennifer Serrano are all seniors who have contributed heavily to their teams' success this season.

And with college coaches scouting across the country to find the next Bonilla, Orlandini or Quilico to solidify their defensive foundation in the coming years, opportunities for liberos that were once limited to partial scholarships and spots as a walk-on have now flourished into the ability to be a significant Division I recruit.

"It's becoming a premier position in the NCAA game and in volleyball in general and you need to have a player of significance there if you want to remain competitive," Jensen said. "If your libero can pass over half the court, then half your problem is solved. And if you're libero is touching the ball, you're going to be winning."