Ever since June 15, 2011, Tuukka Rask’s yearning to lead a team to a Stanley Cup championship has been on overdrive. Rask already has one ring from his days as Tim Thomas’ backup on the 2011 Bruins, but he heads into the 2013 Stanley Cup finals against the Chicago Blackhawks as the go-to guy in net. “Once you’ve seen it, and not being on the ice, I think everybody would like to have that same chance someday,” Rask said during media day yesterday at the United Center. “For me it came pretty early, after our win, and I’m trying to make the most out of it and enjoy myself.” There are a lot of reasons the Bruins are this close to a second title in three seasons, and Rask has to be considered the strongest contender for the No. 1 spot on that list. He just finished obliterating a Bruins team record that stood for 44 years before the sweep of the Pittsburgh Penguins. By surrendering just two goals in the Eastern Conference finals, Rask broke the previous record of five goals allowed in a four-game series by a B’s netminder dating back to 1969. However, he’s not letting his success against the team with the league’s most potent offense give him a false sense of security heading into the finals against the Blackhawks, who have averaged 2.76 goals per game in the postseason. “Not really,” Rask said. “Every series is different. And you kind of have to start from scratch. Obviously you try to feel good about yourself going into a series, but it’s a different team and different things can happen. The base is there, but I think if you’re feeling too confident, it’s going to wind up biting you in the back.” His .985 save percentage against the Penguins was impressive enough. But for the entire 16-game postseason Rask has compiled a .943 save percentage and a 1.75 goals-against average. His save percentage leads the NHL playoffs, while his GAA is 0.01 behind Chicago counterpart Corey Crawford for the league lead.