The last time Carolina and Duke played four times was 37 years ago.

In the days of the old Dixie Classic and Big Four Tournament, Tobacco Road teams could play each other four times in one season. It happened in 1959-60, when UNC beat Duke three straight before losing a fourth game in the ACC Tournament semifinals. It happened again in the 1979 and ’80 seasons, when the teams split four games between the Big Four tourney, home and home series and the ACC tourney.

The Tar Heels and Blue Devils have played in the post-season only once, the fourth meeting of the 1971 season, when Carolina defeated Duke in the semifinals of the NIT in New York. It could have happened again in 1991, when they both advanced to the Final Four before UNC lost and Duke won on Semifinal Saturday.

Carolina and Duke are establishing themselves as perhaps the best two teams in the ACC, which means they could play a third time in the ACC Tournament at the Barclays Center in Brooklyn. The fourth meeting of the season would have to come in March Madness, if they played somewhere in the NCAA Tournament.

One magic bullet of the Carolina-Duke rivalry is that opposites attract. You know, state school versus private school; large student body versus small; mostly in-state students versus mostly out of state. This season, at least, it extends to the basketball programs.

With the loss of sophomore Kenny Williams, the Tar Heels are likely to start three juniors and two seniors from here on out. UNC’s top freshmen come off the bench, and its keys to success are senior post men Kennedy Meeks and Isaiah Hicks playing big to trigger the inside game and rebounding advantage.

Duke’s two senior starters are role players Amile Jefferson and Matt Jones, and the Blue Devils depend on perimeter stars, freshman Jayson Tatum, sophomore Luke Kennardand junior Grayson Allen, all three-point threats.

Look, with both schools playing basketball so well for more than 100 years, it is going to happen sooner or later that they will meet in the NCAA Tournament. It’s looking more and more like this season . . . in the Final Four.