In pairing right-handed defensemen with left-handed defensemen, many NHL teams believe they are following a proven and, seemingly obvious, formula. If defensemen play on their strong side, they will be more effective at their jobs. Conventional wisdom on what works can codify with surprising speed in sports. But when something becomes an accepted best practice, we tend to stop asking how it became so and, more dangerously, we often become blind to the evidence that the practice may not be best at all. Tyler Dellow, senior analyst at The Athletic NHL, believes this is precisely the case with defensemen pairings in the NHL.