Jeff Carter characterized the Penguins' third line as being "real hit or miss" lately.
He's not wrong. There have been a handful of "hits" this season for that group, like a week ago in Anaheim when both Carter and Kasperi Kapanen had goals against a league-basement Ducks team. There's games where the third line is fine, in that they won't score, but they won't be responsible for a goal against, either. Relatively speaking, that's a hit.
There's been minor shuffling in the bottom six that has affected that line throughout the season.