Question: The 76ers–Celtics rivalry is a National Basketball Association (NBA) rivalry between the Philadelphia 76ers and the Boston Celtics, the two teams have the most meetings in which playoffs are a best-of-seven elimination tournament among 16 teams in the Eastern Conference and Western Conference (called divisions, pre-1970), ultimately deciding the league's season champion in the NBA Finals?
Sentence (from "1983 NBA Playoffs"): The 1983 NBA Playoffs was the postseason tournament of the National Basketball Association's 1982–83 season.
Relevant evidence: No