It’s Duke-Carolina week, so let’s start with common opponents.

We’ll be hearing lots of statistics and metrics this week as the Tar Heels and Blue Devils tangle in the first of two contests this Wednesday night in Durham. Nine common opponents to date is one of them, and the results are fairly surprising.

Duke has the edge against the nine common foes, but not by much. In non-conference opponents, the Blue Devils blew out Kentucky by 34 on a neutral court in the season opener for both teams. Five weeks later, the improving Wildcats handled UNC by eight — also on a neutral floor. So that’s plus 42 for Duke.

The other non-ACC team both Blue Bloods played is Gonzaga. Duke lost by 2 to the Zags in Maui after its rally from a double-digit deficit fell just short. Carolina had one of its best nights against Gonzaga, winning by 13 in the Smith Center against the Bulldogs playing without two key starters. Now Duke’s plus points are down to 31.

The ACC schedule has tilted the plus-minus back toward the Tar Heels. Duke won at Wake Forest by 22 after a close first half. We all know what happened in Winston-Salem Saturday; game over by 38 after Carolina scored the first 18 points of the contest. Duke’s plus margin drops to 15.

It goes back to plus 25 when comparing Duke’s home win over Virginia by two points to the Heels’ home loss to the Wahoos by eight points. Carolina won at Pitt by 25 points, Duke by 15 points. Duke won at Georgia Tech by 13, Carolina by 23. The Blue Devils’ plus points are now only five.

The metric goes back to 10 after comparing Duke’s 21-point over Notre Dame to Carolina beating the Irish but 16. But in the most recent common-opponent games, the plus-minus draws almost dead even. The Tar Heels picked up 8 points by winning at Louisville by 10; The Blue Devils, after trailing there by 23, rallied to win by 2 points, dropping their lead to a plus 2.

And in home dates against N.C. State, Duke won by 16 and Carolina by 17, although the game in Durham was much closer than the blowout in Chapel Hill.

UNC has games left against BC, Florida State, Clemson and Syracuse, while Duke has yet to play Miami and Virginia Tech, which lost a total of three times to the Tar Heels.

So right now, by common opponents, the Blue Devils should be favored by 1 point on their home court Wednesday.