Complex sentence: At 2013 U.S. Nationals, Chock and Bates were able to win the silver medal ahead of Maia Shibutani/Alex Shibutani, they were named to compete at the 2013 Four Continents where they won the bronze medal.
Split into simpler sentences: At 2013 U.S. Nationals, Chock/Bates were able to win the silver medal ahead of Maia Shibutani/Alex Shibutani. They were named in the U.S. team to the 2013 Four Continents where they won the bronze medal.