The Bruins are in great shape halfway through the season. They are tied for the NHL’s second-best goal differential at plus-29. They are six points clear of Toronto, the No. 2 team in the Atlantic. They could have a double-digit lead had they not made hash out of the shootout (0-6).



Their No. 1 line of Brad Marchand, Patrice Bergeron and David Pastrnak is elite. Same goes for their No. 1 power-play unit. Tuukka Rask and Jaroslav Halak have few rivals for netminding partnerships. The Bruins are relatively healthy.



Yet for all this sizzle, the steak is somewhat disappointing because of a long-standing deficiency: The Bruins cannot produce during five-on-five action.



Only Winnipeg (2.02) expects to score fewer goals per 60 minutes of five-on-five play than the Bruins (2.03), according to Evolving Hockey, which considers variables such as shot type, frequency and location. As of Jan. 4, the Bruins were averaging 29.02 shots per 60 minutes, more than...