Sarah Baxter doesn’t know how to lose

She is unbeaten, unreal, and wonderfully unaware.

“I guess I run because I’m not good at anything else,” Sarah Baxter says with a tiny grin.

She hasn’t lost a cross-country race in the three years of her Simi Valley High career, yet she once got lost while leading a race on her home course.

“She was supposed to go left, she went right, and everyone was screaming and jumping to get her attention,” recalls Jessie Ellis, a Pioneers assistant girls’ cross-country coach. “A funny story, but there are a lot of funny stories about Sarah.”

She is a three-time state champion and a two-time high school national champion after last weekend’s victory in the Nike Cross Nationals in Portland, Ore. Yet her teammates say her most memorable move occurs before every race, when, at the starting line, she breaks into a dance they call “The Baxter Boogie.”

Says Baxter: “Oh, c’mon, I’m just shaking it out.”

Says teammate Olivia Rosellini with a giggle: “She’s pretty quirky.”

This fall she ran the fastest 5K girls’ time in the 64-year history of the course at the Mt. San Antonio College Invitational in what one expert called “the greatest high school performance ever.” She later set the state meet course record in Fresno. But her teammates says she’s more amazing when she hangs back with them, because, in the middle of a long run, while everyone else is breathless, she’ll start crooning loud renditions of Journey or Elton John tunes.

Says Rosellini: “Out of nowhere, she starts singing, ‘Don’t stop believin’…’ and we’re like, what?”

Says Baxter: “That’s why I like to run with them. When I run by myself, I’m left to my own thoughts, and that’s not always pretty.”

She doesn’t have much choice on that “run by myself” part. As arguably the best girls’ cross-country runner in the country, the 16-year-old junior often competes by herself, running far in front of the pack with a 30-0 record that has rarely even been challenged.

She is so good, beaten opponents ask for her autograph. She is so fast, she can finish a race, towel off, and return to the course to cheer on her teammates.

“We’ll all be kicking toward the finish and she’ll be standing there all rested and waiting for us,” says teammate Sarah Riggs. “It’s just unnatural.”

What is unnatural is how this 5-foot-6, 100-pound girl with long blond hair and a shy smile handles the pressure. She has never lost, so she’s never allowed to lose. Other teams and athletes can have bad games, bad months, even bad seasons if they can figure it out during the playoffs — hello, Lakers — but Baxter can’t even have a bad 15 minutes.

“It’s kind of scary,” she says. “I try not to think about it.”

Every time she steps onto one of those winding dirt paths, everyone is staring at her. Every time she begins running, everyone — from 14 girls to 200 girls — is chasing her. The expectations are so immense that sometimes, at the starting line, her eyes fill with tears. She says a prayer for strength before every race, and often emits a sigh of relief afterward.

But she wins. She always wins. She remains undefeated perhaps because, in her mind, it’s never about winning, it’s just about being the goofy girl in the back of the pack singing oldies and looking for directions.

“When I get really nervous during a race, I just tell myself, ‘OK, I don’t have to get first place for my team to like me,” she says. “When I realize I’m doing this for fun and to be around my friends, it makes it a lot easier to do.”

Could it possibly be that she’s unbeaten because she’s so unaffected? In a city where even some top prep athletes are chest-thumping superstars, could someone really stand out by just trying to fit in? If there’s a lesson here, maybe this schoolgirl isn’t learning it, but teaching it?

“She’s such a grounded kid, she just doesn’t get all that’s happening around her,” says her mother, April. “The most important thing to her is being part of the group.”

She has a car, but no license, because, she says, “I’ve really got no place to be.”

She will hear her latest victory trumpeted during the school’s morning announcements, and the kid in the next desk will loudly wonder, “Who is Sarah Baxter?” and she will just smile and bury her face in a book.

She began her athletic career by playing youth soccer for four years, during which time she failed to score a goal. She also made a brief attempt at baseball, but her younger brother’s throws kept hitting her in the face.

“I don’t really have much of that hand-eye coordination thing,” she says.

Her parents, both California Highway Patrol officers and former competitive runners, steered her toward track because she was fast. It turns out, she indeed loved to run, but so much that she didn’t really care about winning. So her father, Kevin, in a move that will be recognized by caring parents everywhere, began bribing her. He once promised to shave his head if she won junior nationals, which she did, and the bribing soon stopped.

She has since gotten used to winning, so much that when she has nightmares, it’s about losing. Sort of. She says she once dreamed of running up to the finish line at the Mt. SAC Invitational, discovering it was adjacent to a Starbucks, and leaving the course for a latte. The unbeaten champ relates the story and, as with every other charmingly humble tale she tells, she laughs

“You know what the scariest part of that dream is?” Sarah Baxter says. “I don’t even like Starbucks.”

bill.plaschke@latimes.com

Twitter: @billplaschke