Duncan started out as an alpine ski racer . He took part in FIS races from December 1997 and in the Nor-Am Cup from March 2000 , but failed to achieve any major success. He moved to Anchorage in 2002 and graduated from the University of Alaska with a degree in aircraft engineering. He competed in his last ski race in February 2006, and graduated in the same year. Duncan switched to ski cross and immediately finished fourth in April 2006 in his first race, the US championships. He was then accepted into the Canadian national team.
Duncan made his debut in the Freestyle World Cup on January 12, 2008 in Les Contamines , where he finished 33rd. He won his first World Cup points four days later, finishing 26th in Flaine . As a result, Duncan was able to establish himself in midfield. The first top 10 placement followed in February 2009, and in March 2009 he won the Canadian championships. On January 5, 2010, he achieved a World Cup podium finish for the first time as third in the race in St. Johann in Tirol , which qualified him for the 2010 Winter Olympics. In training immediately before the Olympic race at Cypress Mountain , he suffered a broken collarbone and had to end the season prematurely.
In winter 2010/11 a 10th place was Duncan's best World Cup result, at the Winter X Games 2010 he was second. He started the 2011/12 World Cup season with a 3rd place in Innichen . At the Winter X Games 2012 he finished third. On December 21, 2013, he celebrated his first World Cup victory in San Candido, and on the following day he doubled it.
Canada