The Olympics are all about uncertainty. The favorites who fail to match the media hype and the underdogs who come out on top are the reasons why we watch. These London Games have been full of both triumph and tragedy, especially with regards to American athletes.
Here are four who exceeded all odds and put on a performance for the ages at the 2012 Games:
Though she was captain of the U.S. women's gymnastic team, Raisman wasn't expected to compete in the individual all-around. Both Gabby Douglas and Jordyn Wieber were locks for the finals, with Wieber the defending world champion and favorite to win the gold.
Instead, Raisman performed wonderfully in qualifying, and her 15.325 in her floor routine clinched her spot in the final and eliminated her teammate. She continued her solid performance and ended up tied for third in the medal round, losing bronze on a tiebreak.
Though she didn't medal in the event, she surprised everyone with what she did achieve. Raisman went on to win the bronze in balance beam and the gold in floor routine.
Misty May-Treanor and Kerri Walsh
Despite winning back-to-back gold medals, Misty May-Treanor and Kerri Walsh had modest expectations in London. They came into the event ranked third in the world and had plenty of tough competition between them and a three-peat.
There were also other variables that added to their lower expectations in 2012: May-Treanor ruptured her Achilles tendon soon after the Beijing Games and was out of competition for a year. Walsh has had two kids since the 2008 Olympics, but still showed up to London in peak physical condition.
The duo dominated opponents once again, losing only one set on their way to Olympic gold.
Heading into the London Games, Missy Franklin was the talk of women's swimming. The 17-year-old was expected to breakout at the Olympics and become a household name. Expectations for Allison Schmitt were much lower, but she became one of the stars of the Games alongside Franklin.
She began her trip to London with a bronze medal and an American record in the 4x100-meter freestyle, then set another American record on her way to a silver in the 400 freestyle the next day. She followed that with two golds and two Olympic records in the 200 freestyle and 4x200 freestyle relay.
To top it all off, she helped set the world record in the 4x100 medley on her way to a third gold medal.
Not bad for someone who was living in the shadow of Missy Franklin.