Although Fil-American skier Asa Miller has improved through the years, he remains wary of incurring a "Did Not Finish" in the winter Olympics.

A "DNF" can happen even to the best, according to Miller and his father Kelly, citing the case of two-time Olympic champion Mikaela Shiffrin who had consecutive DNFs in women’s giant slalom and slalom earlier this week.

“It happens to all the top skiers, even to the best,” said the 21-year-old Miller, who finished 70th in Pyeongchang four years ago.

Shiffrin crashed in all her runs, spending no more than 20 seconds on the Ice River, the ski course that reared its brutal side to the gold medal favorite.

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Miller's father, an active ski patroller at Mount Hood in Oregon for 27 years, said the key to avoiding a crash is to train and adapt to the course days before any race.

“Every race course, how it’s set and the snow conditions change. You try to understand all the variables and plan how to ski it,” the elder Miller said. “But sometimes you are off and can’t recover from a mistake. I’m sure she [Shiffrin] will come back.”

Shiffrin did come back in the Super-G but her time wasn't enough for a medal finish.

A three-time World Cup champion, four-time slalom world champion and winner of 47 World Cup slalom races, Shiffrin DNFed in a slalom race only three times in the last eight years.

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“Really what is more surprising is that DNFs are so few,” Mr. Miller said. “In the 229 career Olympic, World Cup and world championship races that Shiffrin has entered, she skied out of a race course just 14 times and has done so only three times in the last four years.”

Shiffrin’s previous DNF in slalom before Beijing happened a month ago in a World Cup event in Kranjska Gora, Slovenia.

Miller’s American coach Will Gregorak, who arrived here Thursday, said a fraction of a mistake in a second could instantly drive anybody off the course.

“That’s what happened to Shiffrin,” said Gregorak, who raced in the World Cup 23 times for the US team.

“Skiing is one of the sports where people only pay attention when the Olympics comes around. But the nature of the sport of skiing to go on Shiffrin’s level, it is miraculous that she finished the races, as she does attacking, as hard as she does.”

Gregorak said the most difficult part of the hill is right at the start gate itself.

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“If a skier doesn’t feel the steep course due to unfamiliarity with snow conditions and is not mentally focused, he will be in trouble really fast,” he said.

The men’s slalom contest starts at 10 a.m. on Sunday at the National Alpine Skiing Centre, while the slalom, Miller’s second event, kicks off also at 10 a.m. on Wednesday.