After Friday night's thrilling Sweet 16 action, we have reached a historic moment: Two Giant Killers have broken into the Elite Eight, and each of them was previously a Giant in this very NCAA tournament (Giant vs. Killer matchups are games between teams separated by five or more seeds). No. 6 seed Notre Dame beat No. 11 seed Michigan in the first round, and No. 10 seed Syracuse topped No. 15 Middle Tennessee in the second round in a rare matchup between double-digit seeds.

We await your suggestions for what we should call these two-faced entities. In the meantime, our statistical model says chances are about 50-50 that a Killer will make the Final Four.

EAST REGION

No. 1 North Carolina Tar Heels (Giant Rating: 97.7, on a scale from zero to 100 percent chance of beating an average Killer) versus No. 6 Notre Dame Fighting Irish (Giant Killer Rating: 37.6, on a scale of zero to 100 percent chance of beating an average Giant)

Upset chance: 27.8 percent

In the four most similar GK matchups to North Carolina-Notre Dame since 2007, the Giants went 2-2, outscoring Killers by an average of 6.5 points per 100 possessions.

North Carolina is rolling. Brice Johnson is shooting 61 percent (19-31) in this tournament. When he or his teammates do happen to miss, the Tar Heels are grabbing even more of their own missed shots – a whopping 43.4 percent – than they did in the regular season. And they run at a pace so brisk, it’s hard for outgunned, out-boarded opponents to catch up. Result: UNC has blown out three interesting tourney opponents, with its win probability never dipping below 64.2 percent.

The Irish do have some Giant-Killing resources. In addition to shooting well from both inside and long range, they protect the ball and hit the offensive glass, which gave them the 10th-best offensive efficiency in the NCAA this season (118.2 adjusted points per 100 possessions). They had it all clicking in an 80-76 win over UNC in February, when Notre Dame grabbed 20 offensive rebounds and only turned the ball over twice. Of course, the Tar Heels crushed the Irish by 31 points in the ACC tournament a month later, so Notre Dame has to add a few more ingredients to the mix on Sunday.

For starters, Notre Dame has to keep Demetrius Jackson stoked for steals. The Irish forced very few turnovers this year (14.9 percent of opponent possessions, ranking 333rd), but they did snatch 17 against Wisconsin on Friday night. Jackson’s got to keep gambling.

Second, the Irish must shoot more 3s. They shot 37.1 percent from distance, ranking 58th, but don’t launch many -- fewer than 30 percent of attempts (45-151) in the tournament so far. UNC is most vulnerable (allowing opponents to shoot 35.7 percent on 3s, ranking 236th) from behind the arc.

And maybe most important, Notre Dame can’t let the game get away from it by allowing North Carolina set the tempo. Each of the Tar Heels’ six losses this season came to teams ranked 270th or below in possessions per game. Notre Dame has to drag UNC into a grinder.

The formula is there, and we have seen similar Cinderellas apply it in upsets such as St. Mary’s versus Villanova in 2010. Underdogs battling dominant offensive rebounders need to keep things slow, win the turnover battle and maximize the value of their shots. Our model gives Notre Dame slightly better than a 1-in-4 chance of checking every box.

MIDWEST REGION

No. 1 Virginia Cavaliers (Giant Rating: 94.1) vs. No. 10 Syracuse Orange (GK Rating: 58.9)

Upset chance: 25.9 percent

In the four most similar GK matchups to Virginia-Syracuse since 2007, the Giants went 3-1, outscoring Killers by an average of 3.1 points per 100 possessions.

It’s a good time to be Virginia: The Cavaliers have posted three straight outstanding tournament wins, with Anthony Gill averaging 20.3 ppg and 7.3 rpg. With huge upsets in earlier rounds in its region, Virginia now has clear a path as any team to a national title. If you want to understand how well the Cavaliers are executing at the moment, consider this: On Friday night, Iowa State missed 25 shots -- and Virginia had 26 defensive rebounds. (Really [http://espn.com/mens-college-basketball/boxscore?gameId=400872330].)

But we do need to take at least a moment to appreciate Syracuse as a potential Giant Killer. The Orange, as always, play a 2-3 zone that is effective at shutting down the perimeter. Six players, led by starting guards Michael Gbinije and Trevor Cooney, nab steals on more than 2 percent of opponent possessions, which is how Syracuse forced Gonzaga into 17 turnovers on Friday. This edition of the Orange is also better at shooting 3s than Syracuse has been in recent years (36.1 percent, best since 2010) and much more willing to hoist them (42.5 percent of FGA, highest since at least 2002, the dawn of the modern spreadsheets era). The Orange hit the offensive glass and play at a slow tempo, too, making it very hard to blow them out. In short, they do everything a smart underdog is supposed to, and our model assigns them the highest GK Rating of any potential Killer in the tournament.

Since 2007, Pack-Line Giants like Virginia have faced Perimeter Killers like Syracuse in 34 tournament games, and underdogs have won just six times (17.6 percent). But our model says the Orange are 8.3 points per 100 possessions better than those Killers, on average, while the Cavaliers are 6.2 points stronger than those Giants. In the most similar historical matchups, the higher seeds prevailed by an average of only 3.1 points per 100 possessions. The single best comparison: In 2008, No. 1 seed Kansas almost stumbled on its way to a national championship when it met 10-seed Davidson in the Sweet 16. The Jayhawks managed to hold a sophomore named Steph Curry to just 36 percent shooting that night, and eked out a 59-57 win. Don’t be surprised if Virginia-Syracuse turns out to be a similarly low-scoring and surprisingly tight affair.