LAS VEGAS (AP) — Nathan Chen is out of podium position for the first time in almost four years. The three-time reigning world figure skating champion — and this season’s Olympic gold medal favorite — was fourth Friday night after the men’s short program at Skate America. Chen has long been known as the “quad king,” but fell on his opening quadruple lutz and botched a quad flip combo later in the program. Instead, American Vincent Zhou was is in gold-medal position going into the free skate Saturday. Zhou had 97.43 points to easily lead the 11-man field, followed by Olympic silver medalist Shoma Uno of Japan with 89.07 and American Jimmy Ma at 84.52. Ma has never finished higher than 10th at a Grand Prix.