Going into last night, the 16 teams taking part in the NHL playoffs blocked a total of 1,191 shots in 37 games, an average of 32 per game. None, we hope, was more damaging than the Milan Lucic slap shot that struck Toronto defenseman Mark Fraser on the forehead, between his eyes. Fraser had surgery Thursday to repair a fracture in his “cranial area,” and is done for the season.Also, his shot-block was not intentional, although he was standing between Lucic and the Leafs’ net, doing his job, which likely a dozen times a game means trying to get in front of a six-ounce projectile of frozen-solid vulcanized rubber moving at 90 miles per hour or faster. When you go in harm’s way, sometimes you get harmed. “It hurts so bad,” said Bruins defenseman Johnny Boychuk, who has taken a sheer beating this year blocking shots. “Here,” Boychuk offers a reporter, reaching for a stick, “let me try it on you.” No, thank you. Shot-blocking has become one of the dominant, game-altering aspects of NHL play, maybe the dominant force. Hockey has become a different sport as players have gotten better and better at doing it, and more and more willing to sacrifice their bodies.