When I read Chara's comments, I wonder if he would be more inclined to take a 1-year deal.
Like he said, he doesn't have a number in his head as to when he will retire, whether it be age, games played, seasons, etc. He wants to play as long as he's still effective and enjoys playing.
Because you have the age 35+ rule, where the cap hit will count whether the player is active or not. Because Chara doesn't really have a number in his head as to when he will be done, if they gave him say a 2-year deal, and after next year all of sudden he decides to hang them up, the cap hit hurt the Bruins even if he's retired.
IMO the Bruins are better off upping the AAV (they can afford it next year) along with a full NMC on a 1-year deal than trying to get the AAV down on a two-year deal.
Not that I'm completely against a 2-year deal, just saying it's better for the Bruins to go 1-year with a larger cap hit IMO. I think it gives both parties more flexibility. If they went say 2 years at 4 million per, if Chara retires after one season, he's no better off (he doesn't get the additional 4 million) and now the Bruins will be hit with a 4 million cap hit for a player not playing, at the same time they will need cap space for all the young players who are RFAs that same year.