Four-time champ Chen wins short program with ease

Vincent Zhou competes during the men's short program at the U.S. Figure Skating Championships, Saturday, Jan. 16, 2021, in Las Vegas. (AP Photo/John Locher)

Karen Chen performs during the women's free skate at the U.S. Figure Skating Championships, Friday, Jan. 15, 2021, in Las Vegas. (AP Photo/John Locher)

Madison Hubbell and Zachary Donohue react after getting the top score during the free dance at the U.S. Figure Skating Championships, Saturday, Jan. 16, 2021, in Las Vegas. (AP Photo/John Locher)

Nathan Chen competes during the men's short program at the U.S. Figure Skating Championships, Saturday, Jan. 16, 2021, in Las Vegas. (AP Photo/John Locher)

Alexa Knierim and Brandon Frazier react after receiving the top score in the pairs free skate at the U.S. Figure Skating Championships, Saturday, Jan. 16, 2021, in Las Vegas. (AP Photo/John Locher)

Second-place Amber Glenn, left, and first-place Bradie Tennell smile after receiving their medals at the U.S. Figure Skating Championships, Friday, Jan. 15, 2021, in Las Vegas. (AP Photo/John Locher)

Madison Hubbell and Zachary Donohue perform during the free dance at the U.S. Figure Skating Championships, Saturday, Jan. 16, 2021, in Las Vegas. (AP Photo/John Locher)

Madison Chock and Evan Bates perform during the free dance at the U.S. Figure Skating Championships, Saturday, Jan. 16, 2021, in Las Vegas. (AP Photo/John Locher)

Nathan Chen competes during the men's short program at the U.S. Figure Skating Championships, Saturday, Jan. 16, 2021, in Las Vegas. (AP Photo/John Locher)

Alexa Knierim and Brandon Frazier perform during the pairs free skate at the U.S. Figure Skating Championships, Saturday, Jan. 16, 2021, in Las Vegas. (AP Photo/John Locher)

Vincent Zhou reacts after finishing his routine during the men's short program at the U.S. Figure Skating Championships, Saturday, Jan. 16, 2021, in Las Vegas. (AP Photo/John Locher)