Seems like the Bruins are playing a much improved 5v5 game lately, so I decided to dig into some numbers on Natural Stat Trick to see if there was anything to that. Indeed, there is:
Before Break (51 games): 50.6 CF%, 50.4 SCF%, 50.3 HDCF%
Since Break (5 games): 52.5 CF%, 59.9 SCF%, 64.8 HDCF%
SSS caveat and all, but the adjustments the team has made are paying huge dividends and look to be a recipe for success.
One of those adjustments has been sitting Heinen, as mentioned by cshea above. Heinen's 5v5 CF% is sitting at 48.37% (down around 4th liner numbers) while getting 60.69% offensive zone starts, according to NST. I've been a proponent of his, and while I think there are some valid excuses about how he's played up and down the lineup with many permutations of linemates (including a significant amount of time with noted anchor Brett Ritchie), he just doesn't seem to be good enough. It's odd, because to my eyes, he seems to protect the puck well and make high-percentage passes which you'd think would translate to good possession numbers, but it just hasn't translated to actual shot attempts.