At 36, Daniel Briere is in the waning years of his NHL career and now he'll have to start over again in a new city. The charismatic center was shipped off to Colorado in exchange for P-A Parenteau and a fifth-round pick as Montreal got better in the short term.
Briere is coming off a 25-point campaign that saw him suit up 69 times for the Canadiens and like most of the Habs, he struggled in the puck possession department. That's becoming much more pronounced in the hockey world as advanced statistics begin to capture the hive-mind's imagination and it's worth noting that Parenteau was a pretty decent possession player on a low-ranked Avalanche squad (both teams succeeded in part because goaltenders Semyon Varlamov and Carey Price were so good).
Undoubtedly, Briere still has flashes of excellence, but Parenteau posted better offensive numbers and had been used by the Avs to help shepherd young stars such as Matt Duchene and Nathan MacKinnon at times.
Contract-wise, Colorado gets more freedom, since Briere is on the final year of a contract that will tax the Avs with a $4 million cap hit. Parenteau has the same yearly average on his pact, but Montreal will be on the hook for two more years. In that sense, I can see why Colorado would make this deal, but otherwise it's a pure win for the Habs and I barely even mentioned the fifth-round selection that heads to Montreal as well.