 Complete the following phrase:  The BostonPhiladelphia NHL rivalry, also present in the NBAs Celtics76ers 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 