Every culture has a number considered unlucky because of superstitions. In the United States it's 13. In South Korea, it's four.
The reason behind the fear of the number four, known as tetraphobia, lies in the way it sounds. The Korean word for "four" sounds much like their word for "death."
Tetraphobia is fairly common across many Asian cultures and far surpasses Western propensity to triskaidekaphobia, the fear of the number 13. The superstition permeates through many aspects of society in these cultures. Many elevators in South Korea, for instance, skip the number four or use the letter "F" in place of the number four to represent the fourth floor.
Americans competing in Pyeongchang are learning that you don't need to believe in the "curse of four" to be doomed by the single-digit menace. And given these Team USA athletes' results at the 2018 Winter Games, they may leave South Korea with their own fear of four.
Mikaela Shiffrin — Alpine Skiing, Slalom
In her signature event, defending Olympic slalom gold medalist Mikaela Shiffrin finished fourth just a day after winning gold in the giant slalom. She was also wearing the No. 4 bib.
Ben Ferguson — Snowboarding, Halfpipe
Ben Ferguson finished on the podium in three of the four Olympic-qualifying contests, and he was the first U.S. men’s halfpipe rider to qualify for the 2018 games. But after posting a big score in the halfpipe qualifying and easily advancing to the finals, Ferguson, wearing bid No. 4, finished just off the podium in fourth place.
Lindsey Jacobellis — Snowboarding, Snowboard Cross
Lindsey Jacobellis, the most decorated women’s snowboard cross athlete ever, recorded a fourth-place finish at her fourth Olympics, also donning the No. 4 bib.
Maddie Mastro — Snowboarding, Halfpipe
Wearing bib No. 4, the young American snowboarder had a disappointing end to her Olympic debut, crashing out three times in the women’s halfpipe finals to finish 12th out of 12 women in the finals.
Ryan Cochran-Siegle — Alpine Skiing, Men's Combined
In his Olympic debut, Ryan Cochran-Siegle clipped a gate during the combined downhill and wiped out. The 25-year-old was also wearing bib No. 4.
The Americans aren't the only ones impacted by the "curse of four." These Athletes from other Western countries who donned the No. 4 bib during their competition may also have been jinxed.
Austrian Stephanie Brunner — Alpine Skiing, Giant Slalom
Stephanie Brunner crashed in her first run of the giant slalom and failed to finish.
Australian Britteny Cox — Freestyle Skiing, Women's Moguls
The defending world champion in women’s moguls finished 5th.
Dutch Ireen Wuest — Speedskating, Women's 100m
The most decorated speed skater in Olympic history skated in the fourth pair and finished 9th in the women’s 1000m. A day earlier, Wust won gold in the women's 1500m. She skated in starting pair No. 11 in that event.
Kazakhstani Denis Ten — Figure Skating, Men's Short Program
A bronze medalist in Sochi, Ten skated fourth in Friday’s men’s figure skating short program and finished 27th, failing to advance to the free skate event.
Sweden's Hanna Falk- Cross-Country, Women's Sprint Classic
After finishing first in her heat at the quarterfinals and third in the semifinals, Falk came in fourth in the finals of the women's sprint classic.
As for Shiffrin’s gold in giant slalom on Thursday, she was wearing bib No.7, a lucky number in South Korea.