But while others may resort to name-calling, pranks and household spats, San Pasqual's Eli and Zoe Scandalis prefer to duke it out on the tennis court.

“We're very competitive,” said Eli, a junior. “It gets intense out there.”

His freshman sister agreed.

“We definitely go at it on the court,” Zoe said. “Eli definitely doesn't like getting beat by his younger sister, and I definitely don't like getting beat by him.”

Two weeks ago, Zoe defeated San Marcos' Lacey Smyth 6-4, making Zoe and Eli the first brother and sister to have won Valley League titles as freshmen.

On Friday, Zoe competed for the CIF San Diego Section individual title, where she fell to Gabi DeSimone of Cathedral Catholic High 6-7 (1-7), 2-6.

The postseason has sparked yet another competition in the Scandalis household, this time to see who can rack up the most titles in high school tennis.

Zoe said she's glad to be in the driver's seat for once.

JOHN GASTALDO / Union-Tribune Junior Eli Scandalis and his sister have been playing tennis since early childhood. “We're very competitive,” he said. “It gets intense out there.”

“Basically, we've done the same thing our whole lives,” she said. “Like with academic awards, I would get the same ones he did, and it was like I was following him. This will be the first bar I set for him.”

But that doesn't stop Eli from offering some brotherly advice and giving her tips on how to improve her game.

“She gets a little irritated,” Eli said with a laugh.

“He tries, but I don't exactly like it,” she said. “Especially because I can't give it back to him because I'm younger.”

Eli and Zoe got started in tennis at about ages 6 and 4, with encouragement from their father, Will.

“My dad got us started in it,” Eli said. “He thought it would be a good sport for us to play. It's a fun game that you can keep improving in. You can never really get too good.”

Zoe doesn't know how old she was the first time she got on the court, but she does remember one of the first times she hit a tennis ball.

“I remember my dad, he used to feed me balls in the house, and I think I hit a window,” she said. “My mom didn't like that very much.”

Will, an athletic trainer and former professional triathlete, said he's glad his children took to the sport.

“It's not just a physical thing,” he said. “It can be a physical thing, but you can also be successful by seeing the game, almost like math – like chess. In tennis, you have to be a problem-solver.”

Will often has to take on that role when umpiring Eli and Zoe's matches.

“Neither of them likes to lose, so I have to be the mediator sometimes,” he said. “And they're so good about it. When I say, 'That's enough,' they drop it. We leave it on the court.”

For the most part, anyway. There's plenty of good-natured ribbing at home, Eli said.

“You've got to be ready (to play Zoe), or else you've got to live with it for the next couple of days,” he said.

“(We play for) bragging rights at home,” Zoe said.

Some things are just sibling nature.

 Kristina Crawley: (760) 752-6744; kristina.crawley@tlnews.net