Flames’ Klapka just might be NHL’s nicest tough guy. He’s learning to be mean

LAS VEGAS — The world-class smile stretching across Adam Klapka’s face looks like that of a man who has just been told the team bus is stopping for ice cream. It almost never disappears, which is just a small part of why the Calgary Flames winger is the nicest six-foot-eight, 235-pound man you’re ever likely to meet. However, one of the keys to his longevity in the NHL revolves around knowing when to ditch his charm to make somebody regret wandering into his postal code. “You just have to be mean,” he said, somewhat unconvincingly. “I don’t like the fights…