The Celtics and 76ers are set to face off in Game 7 of the first round of the NBA playoffs on Saturday night, and let’s just say it’s a matchup we’ve seen before . This will be the ninth time the two sides have faced off in a Game 7—the most of any two teams in NBA history. The do-or-die rivalry began all the way back in 1959, and has been played as recently as just three years ago. The Celtics hold a 6–2 edge in the decisive meetings, and hope to continue that trend in Boston on Saturday. Below we take a look at the Game 7 history between the Celtics and 76ers. (Home team in bold) Year Round Winner Loser Score How far did the winner go?…