Brad Kaaya of Chaminade, Jalen Greene of Serra in position to excel

Never doubt the intelligence of a third-grader.

When Brad Kaaya was 8 years old, his youth football teammates voted him quarterback because he could throw the football the farthest.

“It was a good vote,” said defensive lineman Brody Illuis of Sherman Oaks Notre Dame High, one of those smart third-graders. “We went to the championship that year.”

Kaaya has led West Hills Chaminade to a 5-1 record this season and accepted a scholarship to Miami. But Kaaya and Chaminade have a big test in a Mission League road game Friday night against unbeaten Gardena Serra (6-0).

On the other side will be Boise State-bound quarterback Jalen Greene of Serra, who has his own intriguing tale on becoming a quarterback.

He was a 14-year-old freshman receiver at Serra when the coaches asked for volunteers to play quarterback.

“I put my hand up,” Greene said.

Who says coaches are the only ones who know how to discover talent?

Kaaya and Greene are examples of what can happen when determined, talented individuals are given a chance.

Kaaya, 6 feet 4 with the ability to quickly locate second and third options among his receivers, has passed for 1,638 yards and 11 touchdowns with two interceptions.

Greene, 6-3 with the ability to scramble, has passed for 1,239 yards and 16 touchdowns with three interceptions and has run for 453 yards and six touchdowns.

“He’s really athletic,” Kaaya said of Greene. “He knows how to make plays. I watched him that whole fourth quarter against Notre Dame. He took over. He’s a guy I have a lot of respect for.”

Ditto for Greene about Kaaya: “Brad is cool. We’re always competing. He’s a great kid. He has a great pocket presence.”

Each quarterback has improved immensely. Kaaya was a backup at Encino Crespi until transferring to Chaminade as a junior. UCLA and USC made scholarship offers this month.

“His mechanics are ahead of most quarterbacks his age,” Chaminade Coach Ed Croson said.

Greene has guided Serra to 16 consecutive victories since a 28-20 loss to Chaminade in league play last season. It was a turning point for Greene, who was trying to do too much.

“I relaxed and let the game come to me,” he said.

Chaminade and Serra played twice last season, with the Cavaliers winning the last game in the Western Division final that ended on a controversial on-side kick.

“It’s pretty much our biggest week of the season,” Kaaya said.

Croson has been preparing for Serra since summer practice began. There are plays he has put in for the Cavaliers and others he’ll be saving for an expected playoff rematch in December.

Serra Coach Scott Altenberg has many players to turn to, including defensive back-running back Adoree’ Jackson and receiver Jordan Lasley, a UCLA commit. But Greene is the player who makes things happen.

Notre Dame Coach Kevin Rooney knows both teams well, having lost to Serra, 20-13, in double overtime and to Chaminade, 46-43.

“Chaminade is very talented and so is Serra,” Rooney said. “Based on the scores of our games, Serra might be a little tougher defensively.”

But Rooney isn’t willing to predict a winner.

Maybe it’s best to ask a third-grader. They’ve been known to get it right on occasion.

eric.sondheimer@latimes.com