US snowboarder Lindsay Jacobellis has won just about everything there is to win in her sport - except Olympic gold. And that was only because she took an unnecessary risk in the snowboard cross final at the 2006 Winter Games in Turin: Jacobellis had a gigantic lead over Switzerland's Tanja Frieden with two jumps to go and already felt like the sure winner.
So much so that she got cocky on one jump, tried a "grab" where she touched her board with her hand, but fell in the process. Frieden passed, Jacobellis came in second.
In the 2018 Champions League final, Loris Karius achieved sad fame: with two fatal mistakes, the goalkeeper initiated Liverpool FC's 1:3 defeat against Real Madrid. First he threw at opposite number Karim Benzema, who casually netted. Then Karius let what should have been an unmarked long-range shot from Gareth Bale slip through his hands. The keeper earned taunts and jeers. It wasn't until long after the game that he reported that it was a risk for him to still be on the pitch at all - because he was playing despite concussion.
"In hindsight, I certainly should have been much more offensive about it publicly," Karius told Sport Bild almost two years after the game: "I had a concussion after a blow from Sergio Ramos, which limited my spatial vision." Whether the medical department of the "Reds" or Karius himself made the decision to continue playing is unclear. But the risk was not worth it, neither for Liverpool nor for the current substitute goalkeeper of Union Berlin.
Super Bowl 49 between the Seattle Seahawks and the New England Patriots in February 2015 had a memorable ending. The Seattle Seahawks needed a touchdown in the closing seconds to win the biggest trophy in American football. And actually, it was looking very good: They had three attempts left to carry the ball the two yards into the end zone in the final minute of play. With the dazzling run offense, failing to do so was almost an impossibility.
But Coach Pete Carroll decided to go with a surprising, but just that much riskier, pass play. What happened was inevitable: the Patriots intercepted quarterback Russell Wilson's pass, gained possession of the ball themselves, and pushed their lead to the finish line. The courage to take unnecessary risks was the Seahawks' undoing in one of the most memorable finishes in Super Bowl history.
Linford Christie's career ended with a bang. Not, however, with the 100-meter sprinter's title defense at the 1996 Olympic Games in Atlanta, but with the starting gun for the Games' sprint final: In his final run on the very big stage, the Jamaican-born Briton risked too much, going out of the blocks too early in two starts and being disqualified for it.
After protesting for just under three minutes, Christie left the tartan track after all. An undignified end to the Olympic career of one of the defining sprinters of the 1990s.
American Football once again, but this time in a particularly curious way: With surprising trick plays, teams try time and again to catch their opponents off guard with unconventional lineups or plays. But the risk that coach Chuck Pagano and his Indianapolis Colts took in his 2015 attempt against the New England Patriots ended in fiasco: The players who were otherwise supposed to protect the quarterback on possession lined up yards away. The plan was probably to tempt the Patriots into a jump start.
In the end, however, the inevitable happened: the opponent obliged and cashed in on the lonely quarterback with an overwhelming number of players. It wasn't just the US commentators who wondered what this trick play attempt was all about:
The US marathon runner Fred Lorz almost became Olympic champion in 1904 with a cheating attempt that was as risky as it was brazen: Lorz ran the first 14 kilometres at the Olympic Games in St. Louis before unceremoniously switching to his trainer's car for the next 18 kilometres.
Curious: At first no one noticed the exit. Lorz crossed the finish line unchallenged and was already announced as the winner before spectators unmasked him.