AUBURN – Thirteen months separate the birthdays of the skiing Eretzian sisters, Tara and Karly.

It’s the next-closest fate to being twins, and it’s probably the ideal window for the brand of sibling rivalry that television sitcoms made famous.

You try ignoring the constant comparisons in the classroom and on the mountain. After Tara graduated from Leavitt Area High School in 1997 and chose to continue her skiing career at Plymouth State University, it’s probably no surprise that Karly packed her bags for Syracuse University a year later.

“It was kind of cool, because we skied in different regions for different schools and still met up at nationals,” Karly said. “There always has been good competition between us.”

If that invisible nudge to excel and outshine was natural, however, so is the closeness that other best friends with a track record of 20 to 30 years will never understand. So are the tendencies to think alike and finish the other’s sentences when the answers matter most.

Easy to understand, then, why Tara and Karly Eretzian are working together again as alpine ski coaches at neighboring, potentially rival schools.

Tara leads the Edward Little High School team, while Karly’s in charge at her alma mater. The teams train together daily at Lost Valley under a tutelage that both coaches and their teams consider a job share.

“I coach her kids and she coaches my kids,” said Tara. “One of the first things they asked me this year was, ‘Are we training with Leavitt?’ It’s great. I love it.”

“It is definitely strength in numbers. It’s a strength that we’re related and that we both have the same passion,” Karly said. “We skied together in high school and competed in college, so our passion for skiing has always fed off each other’s passion.”

The family connections are a helpful boost at a time when two traditionally proud programs need it most.

Participation numbers are dramatically down at both schools. EL fielded more than 30 skiers with full ‘A’ and ‘B’ teams at the start of this decade. Now, it’s a battle to draw a double-digit number of boys and girls, combined.

There are no full-time female alpine skiers at Leavitt this season.

“It’s not like it used to be. She and I talk about that all the time,” Tara said. “The problem is money. It’s not a cheap sport. We love it, and we’re trying to promote it.”

EL’s and Leavitt’s small, but tight-knit teams benefit from two coaches who think alike but draw from divergent backgrounds and areas of expertise.

“We have different styles that work together well, and the kids can sense that, also,” Karly said. “She’s a slalom skier and I’m giant slalom. She definitely has a strong technical background. I’m a lot about the educational process. I’ve always felt that skiing is an education in itself.”

In a time when coaching turnover is higher than ever and the number of eager, young replacements is at a low ebb, the Eretzians gravitated to the labor of love in different ways.

Tara knew she wanted to coach from the moment she left Plymouth State. Those desires took her to nearby Waterville Valley Academy, where she enjoyed the snow and the students but wasn’t satisfied with the job.

That brought her home to a position as an educational technician at EL, where she now teaches math.

“I didn’t know what I wanted to do when I got out of college,” she said, “but I knew skiing would be involved somehow.”

Karly, a graphic artist, admittedly began coaching middle school students out of fear.

“I was afraid I would never ski again,” she acknowledged. “That’s usually what happens. I started coaching mostly so I would have a reason to keep skiing.”

Then again, it would be hard for anyone familiar with the women’s family to imagine them not coaching.

Working with young people is a family tradition in the Eretzian household. Tara and Karly’s mother, Barbara, was superintendent of schools in Auburn. Their father, David, is principal at Franklin Alternative School.

“We can sit around a table with our parents and talk about coaching for three hours at a time,” said Karly.

And when it’s only the two of them, the conversation isn’t much different.

“We’ve always been there for each other,” Karly said. “It’s just nice to have someone who is going through the same things with her team that I am. We’re just having a great time.”