Anyway about that plus minus thing... we all know that it matters if your in the + on a sucky team, like Subban and Gorges last year or if your in the minus on a really good team... + it's more important to look at it with defense players.
Over the years, some players had something like +30 but there's a lot of factors that comes into play. Linemates? What his role on the ice?
It's all about even play, that doesn't count with special teams... Montreal didn't score a lot of goals at even play last year
So for patofqc... When you think that Montreal sucked big time for scoring goals last year... and you add it to the fact than Plekanec was used a lot of time against the best offensive lines where his role was often to shut them down and he had crappy linemates all year long... it tends to give you some bad +/-.
Plekanec have a positive +/- over his career... give the guy a break.