NASCAR had an eventful day at the New Hampshire Motor Speedway on Sunday, with the race temporarily interrupted by rain. When racing resumed, drivers had to switch to wet weather tires, as mandated by NASCAR. The innovation is somewhat new in the sport and, as a result, the operation was a little disjointed. NASCAR was making all the calls on tires, rather than individual racing teams. That made for a chaotic day for drivers, who could relay information about their tires even though they weren’t necessarily free to change tires. The governing body explained after the race that the goal is to e…