LAS VEGAS—Nathan Chen doesn’t miss. As he has done since his last loss at the Pyeonchang Olympics—yes, nearly three years ago—the dynamic Chen was nearly perfect and rather playful in winning the short program Saturday at the U.S. Figure Skating Championships on Saturday. Seeking a fifth straight national title, something no man has done since Dick Button from 1946–52 with seven, Chen put out the most difficult routine that any man anywhere attempts. He hit a quadruple lutz, triple axel and an excellent quad flip-triple toe loop combination in scoring 113.92 points. “I’m quite happy with the skate,” said the two-time world gold medalist. “Some of the jumps, the landings were a little bit shaky, especially the lutz, but I’m glad that I was able to pull through lutz and get to the axel and then do a combo in the second half. I don’t know if I’d ever done …