That’s indeed what happened. Over time, doctors who treated tough cases went on to excel. For a clinic’s first 100 cases, doctors who stuck with less complicated patients enjoyed a higher success rate. After 100 cases, doctors who had treated more difficult patients all along snuck into the lead, because benefits from their learning kicked in. At 400 cases, their success rates surpassed those of the “easy case” doctors by 3.3 percent, and their learning continued. Their looping had made them the top performers.
