I think the biggest erosion in Smith's game is his decision making without the puck in the offensive zone. He seems lost on where to be the majority of the time and when the puck is on his stick, the flow of the play dies. His work ethic is there. I really don't know what happened to the guy. Maybe he just is an odd fit for Monty's system.
Good observation. I think part of that is due to lack of confidence. He's second-guessing, and this is probably the result.
Could maybe be a system issue, at least in part, but I think he started to decline last year. His start to last season was poor. Rallied somewhat in the second half, but then in the playoffs against the Canes he was basically invisible: 0 points and -5 though 7 games. He's only 33 but some guys just fade earlier than others. Probably best he can realistically hope for from here if he wants to extend his career is to land on a lowly team with little pressure and try and carve out a solid middle-6 role for another couple of years.
It's a shame. I liked the signing when he came to Boston, thought the money was fine, and his first year was quite good. But it just hasn't panned out since then.