Dobson was acquired from the Islanders in a sign-and-trade, so the Canadiens were able to lock him up to an eight-year deal and get a $5.5M AAV raise from his previous contract. Dobson is one of the NHL's best goal-scoring defensemen, having posted double-digit goals in four straight seasons. He ranks 14th among blueliners with 46 goals during that stretch. In Montreal, he'll have to battle with the likes of Lane Hutson for PP1 time, and his most likely path to that usage is if Montreal uses both of them on the same unit.
