The tension in the interval start race comes down to watching the clock. The seconds tick, the time checks pass, the squirm of the of the skier in the leader’s chair only quelled after the top-prospects slide past the finish — and there’s only a reference to time back. On Dec. 12, that was France’s Maurice Manificat, the thirty-two-year-old skate skiing star, residing where he often belongs, sitting in the leader’s chair in Davos,...