I would say they're hard to play against in the sense that they're very consistent, to use the cliche, they 'roll 4 lines' really well most nights so they keep the pressure on, and most of the time they hold their structure defensively and are hard to break down. When teams play the Bs they know they're in for a battle where they'll need to earn their chances and won't get many freebies. I see more of that than them being physically intimidating or hard-hitting.
There's different ways of being tough and the Bruins have their chosen brand, I guess, and it doesn't go unnoticed by opponents. Whether they need more of other types of toughness is an open question.
