First thing you want from your 4th line is to NOT be a liability. Regardless of their physical makeup, you want to know that you can throw them out there and they won't cost you on the scoreboard.
After that, you typically want them to either create energy via faster, less physical guys that "buzz" around and create havoc, or you want them to be big and physical and be some sort of crash line that instills fear in the other team. Sure you'd like a goal here and there, but in the end that's just a bonus.
Bylsma, and now MJ it seems, want to have "grit", which is a word I've grown to despise these last 4 years. Grit is fine, and having players that fit that description is fine too, but when they're incapable of being effective at the role they're given, you don't keep putting them out there based on some vision you have for them. You look at reality, like Sill and Adams being hemmed in their zone when the other 3 lines kept creating momentum, and you adjust accordingly.
We'd all love to have a Martin-Cizikas-Clutterbuck as our 4th line. We'd love to have Ryan Reaves, but MJ doesn't have the type of players to play in that role. However, he does have enough speedy agitators to create an effective 4th line, yet somehow they'll literally ALL be in WBS by the time everything is said and done.
I don't care how silly it is and how it makes me sound: I hate Craig Adams more than I've hated any other player to ever wear a Penguins sweater. It's not even a hockey thing, it's a right or wrong thing. In every walk of life, I've always despised people who somehow somehow manage to stay afloat regardless of incompetence, and others who deserve way better keep languishing because those in charge are too stupid to see what's what.
I can't wait for the end of the season where this guy is finally gone. It'll be worth an early exit just knowing I never have to see him in the lineup ever again.