If you're the superstitious type, you've likely taken notice of Curve 13 of the Flying Dragon Course in Beijing. It's the one that caused all sorts of difficulty for the luge events and today it ended the Olympic medal hopes of Great Britain's two-man bobsled.
While Curve 9 proved to be the troublesome bend at Pyeongchang 2018 for those throwing themselves down an ice track at speeds exceeding 80 mph, it's No. 13 that has been unlucky in Beijing for the lugers and Great Britain driver Brad Hall, who misjudged it in the third heat to leave Britain's hopes head over heels with the team skidding along the course.
"You go into survival mode, it's the tightest grip you have," GB brakeman Nick Gleeson said. "Thankfully it was a small crash compared to some of the ones I've had. It's an adrenaline rush -- not the most ideal one -- but I'm glad we're safe and sound and we went back up for the fourth run."
That tricky turn -- on the verge of the finale to the course and just before the double chicane of 14 and 15 -- caused carnage on Monday in the first two legs of the women's singles luge. The course is in the shape of a dragon, so it's the creature's tail that is tripping up the hopefuls. The lugers had only limited time on the course -- alongside the track walk, they had six practice runs to learn its intricacies -- before they competed.
Back on the first Monday of the Games, one of the precompetition favorites, Germany's Julia Taubitz, lost control on that bend, flipped her luge and skidded. The same fate befell the USA's Emily Sweeney.
"That was hard," Sweeney said. "It's a tough spot you have to come out right, if you're not correct coming out then the track gives away and you're weightless. If you're crooked a little bit in your sled or you're not in the right spot, it'll get you."
Austria's Madeleine Egle, who took bronze at Pyeongchang, also flipped on that bend, but she explained the intricacies of the problem: "It's a real technical curve. You have some options to slide this curve.
"It's just a little bit weird because the curve's going to the left side, but then there's a straightaway but not a real straightaway because of the two 14 and 15 curves. So it just needs to be calm and needs to have the right direction when you get out of the curve because you can't steer anything into another direction, otherwise you will flip over."
Effectively, it leads you steering against the momentum you're heading in.
Those who competed in the men's double luge also found it tough, with Zack Digregorio -- one half of the USA pair -- saying it requires the need for a "consistent slider" but warned that "anyone [who is] off even a little bit can flip there."
It was too much for Latvian brothers Andris and Juris Sics who were tracking well, until they entered Corner 13 only to make their medal-ending mistake.
In the men's singles it was Curve 9 that did for Felix Loch while David Gleirscher's run was interrupted by a mistake on that now-infamous No. 13.
"All in all, for me it was s---" he said afterward.
Traditionally, there are fewer crashes in skeleton than luge. Germany's skeleton hopeful Tina Hermann rooms with Taubitz and she said the experience is different, but still tricky.
"It's a difficult one for us, entering 14 and 15," Hermann said. "It's really hard to find the perfect line."
But the skeleton sliders all managed to get through the course relatively unscathed. The monobob also passed without drama, but it has proved troublesome for the two-man bobsled early in this second week.
The Canadian team piloted by Justin Kripps said it had difficulty with it during the first heat on Monday as they made a "big mistake" there, and it ended up being the unlucky curve that ended GB's hopes as they clipped the wall and ended up face down in the ice.