The Boston–Philadelphia NHL rivalry, also present in the NBA's Celtics–76ers rivalry, dates back to and was most intense in the 1970s, but the rivalry renewed its intensity in the 2010s. In the early 1970s, both the Bruins and Flyers played similar styles that reflected perfectly on each teams respective city, with the Bruins being known as the "Big Bad Bruins" and the Flyers as the "Broad Street Bullies." The most vicious rivalry of the era hit its peak in the 1974 Stanley Cup Finals, with the Bruins, led by Bobby Orr and Phil Esposito, and Flyers, led by Bobby Clarke and Bernie Parent, in an intense grudge match. The Flyers would complete a stunning upset, defeating the Bruins in six games. The two teams would meet each other again in the semifinals in the 1976, 1977, and 1978 playoffs, but would not meet each other again in the playoffs until 2010. Prior to the playoff meeting, the two teams squared off in the 2010 Winter Classic at Fenway Park, with the Bruins winning the game 2–1 in overtime. When the two teams met in the playoffs that year, the Bruins stormed out to a 3–0 series lead, but the Flyers would complete a stunning comeback, winning the series four games to three, which also included overcoming a 3–0 deficit in the decisive game seven, and end up in the 2010 Stanley Cup Finals. The Bruins would get revenge the next season by sweeping the Flyers in the conference semifinals en route to their 2011 Stanley Cup win. In total, the Bruins and Flyers have met in the playoffs six times, with each team winning three series.