Both the Rangers and the Penguins seemed to have gone "all in" for this fighting crap, and its probably going to cost both teams the series. It might even be the same with the Blues-Sharks series.
It seems to me that the experienced underdogs like San Jose and Philly are goading the opponent into fighting, while relative newcomers New York and St. Louis are taking the bait against inferior competition.
I guess my point is I don't see what Pittsburgh, New York, and St. Louis are gaining by turning each game into a free-for-all.