Kasper attended the Burke Mountain Academy in Burke , Vermont and started in FIS races from December 2004 . In 2007, after some successes, he was accepted into the junior team of the US Ski Association. In February of the same year he contested his first race in the Nor-Am Cup . At the Junior World Championship in Garmisch-Partenkirchen in 2009 , he won the bronze medal in slalom. In the 2009/10 season, Kasper had his first big success. He won a Nor-Am race and took five other podiums. He was also the winner of the slalom classification and third in the overall classification.
On November 15, 2009 Kasper made his debut in the World Cup and was 59th in Levi's slalom . In the Kitzbühel slalom on January 24, 2010, he qualified for the second run for the first time, but remained without World Cup points due to the large time gap. He won this for the first time two days later with rank 24 in the Schladming night slalom . He was nominated for the 2010 Olympic Games and finished 24th in the slalom in Whistler .
After Kasper had not scored in the World Cup for almost a year, but had good results in the European Cup in the 2010/11 season (he won the slalom classification and was fifth overall), he achieved two top 15 placements in January 2011. The following month he reached 15th place in slalom at the 2011 World Championships in Garmisch-Partenkirchen . He was able to improve further and at the end of February achieved a top 10 position for the first time in Bansko . On March 6, 2011, he achieved the only World Cup podium finish of his career with second place in the slalom of Kranjska Gora (at the same time as Axel Bäck ).
In September 2011, Kasper was operated on on his hip , after which he could only start snow training again at the beginning of November. Nevertheless, he reached fourth place at the beginning of the 2011/12 season in the slalom of Beaver Creek on December 8, which remained his best result of the season. In two other World Cup slaloms that winter, he was among the top ten. In spring 2012 he had to undergo another hip operation. On December 7, 2012, Kasper suffered severe knee injuries during slalom training before the World Cup race in Val-d'Isère (cruciate ligament and meniscus rupture in the right knee and an internal ligament rupture in the left knee). After a year break, he was able to classify himself twice in the points in the 2013/14 World Cup season , with an 18th place being his best result.
After a disappointing start to the 2014/15 season (no World Cup points in seven races), he had to undergo another operation, this time because of cartilage damage. The subsequent operation resulted in complications that required three more operations. For two and a half years he could not contest a single race. During this time he graduated from Dartmouth College with a degree in economics . In November 2017 he dared to make another comeback. He won several FIS races and a slalom in the Nor-Am Cup. On January 14, 2018, he finished 20th in the Kitzbühel slalom, which enabled him to take part in the 2018 Winter Olympics in Pyeongchang . There he was eliminated in the second run of the slalom and reached 9th place in the team competition. Finally, on April 24, 2018, he announced his retirement from top-class sport.
United States
