Whereas the Celtics versus the Lakers has long been held in high regard as the NBA’s greatest rivalry, it has only been esteemed in this way because of the number of NBA Finals appearances the two have had together. Considering two teams from the same conference or division cannot meet in the NBA Finals, Boston versus Philadelphia could never equal that particular total.

But what the Boston versus Philadelphia rivalry does have is longevity, tremendous pedigree, and records on its side. No two teams have met in the playoffs as much as these two, not even Celtics versus Lakers - the two franchises have matched up in the postseason 19 times overall, five ahead of the second-place rivalry of the Celtics versus the New York Knicks. And the Celtics vs Knicks series does not have the same degree and volume of pedigree as this.

During the days of the great Boston Celtics teams, the Celtics seemingly always had to get through the Nationals/Sixers to even get to the NBA Finals. The two teams met in the playoffs in all of 1953, 1954, 1955, 1956, 1957, 1959, 1961, 1965, 1966, 1967, 1968 and 1969 – in simpler terms, the Celtics and Sixers met in the playoffs 12 times in a 17-year stretch, nine of which were in the Division Finals.

The first series went the way of the Celtics, prevailing 2-0 with two six-point wins led by 35 points per game from the legendary Bob Cousy. However, in the next three series over the next three years, the Nationals swept the board, winning all three series behind the play of Dolph Schayes, Hall of Famer and one of the 50 Greatest Players of All-Time.

To reverse this trend, the Celtics needed another all-time great of their own: Bill Russell.