Just based on the way the races played out and the comparable degrees of difficulty. Basic physics and psychology. Being able to run in a group and behind other runners allows drafting, energy conservation and helps the runner to be pulled along. That is why so many high school records get set in pro races. So ideally you would choose a fast race where you could run in a group running above record pace and where you could stay off the front. If I recall Hutchins was able to draft for the first six laps and then had to run from the front the rest of the race.
But in any event the time is what matters in setting a record.