Track and field, like all sports, is hibernating at the moment, giving plenty of room for idle thoughts. The present situation is dire, but I’ve tried to periodically distract myself with what the running world will look like when the racing resumes. One concept that’s always been interesting to me is round number records. The most famous of which, the four-minute mile, is run with such regularity now that its significance is lessened with each passing decade. Instead, I’m looking at that next set of barriers that help usher in a new digit to an event.