No. 4 Louisville (42 percent win probability) vs. No. 7 Michigan StateLocation: SyracuseWhen to watch: At 2:20 p.m. EDT on CBSPower ratings: Michigan State 88.2, Louisville 86.3Upset probability: 58 percentPlayer to watch: Denzel Valentine, Michigan StateAs befits an East Regional that saw its top two seeds lose on the tournament’s first weekend, this is a strange matchup. Louisville is the better-seeded team, but as a No. 4 they’d easily be the black sheep of the Final Four if they prevail here (No. 1’s Kentucky and Wisconsin are already in, while the South winner will be no worse than a No. 2 seed). Plus, this game qualifies as a “fake upset” if inferior seed Michigan State wins, since both Las Vegas and the FiveThirtyEight model throw the seed numbers out the window and consider the Spartans a stronger team than the Cardinals.So when deciding the most upset-heavy region in an otherwise chalky NCAA tournament, do you go for the (fake) upset or the (real) upset?It could come down to which team’s forte wins the day — Michigan State’s offense, or Louisville’s defense. Both units rank among the nation’s best, and their respective strengths do a decent job or mirroring each other. The Spartans shoot well and avoid turnovers; the Cardinals are at their best when taking those attributes away. But it’s not a perfect match. Louisville likes to keep teams off the line, a fate Michigan State might prefer given their horrendous free throw percentage, and Michigan State’s offensive rebounding could exploit a Louisville frontcourt that’s nothing special on the defensive glass.Either way, the less-exciting battle between the two teams’ weak points — Louisville’s offense versus Michigan State’s defense — is where the Spartans gain their predicted edge. While they won’t force many turnovers, Michigan State loves to limit opponent shooting percentages (particularly on 2-pointers, by far Louisville’s most efficient zone of the court) and the Spartans have the rebounding advantage over the Cardinals at that end of the floor as well.Add in an uncharacteristically poor 3-point shooting Louisville team (by Rick Pitino standards), and this year’s “non-vintage” Spartans could win with the defense-and-rebounding formula of a typical overachieving Tom Izzo Final Four squad.Check out FiveThirtyEight’s March Madness predictions. After an exhilarating Saturday that saw Wisconsin beat Arizona yet again with a Final Four on the line, followed by undefeated Kentucky barely squeaking past a Notre Dame team that outplayed them for a significant portion of the night, what can Sunday’s Regional Final games do for an encore? For starters, there’s another terrific No. 1 vs. No.2 matchup in which the underdog could make school history. There’s also a fake underdog story that will decide the only wacky region of this year’s tournament.Read on for more of what to watch as the last two Final Four berths of 2015 are set:No. 1 Duke (59 percent win probability) vs. No. 2 GonzagaLocation: HoustonWhen to watch: At 5:05 p.m. EDT on CBSPower ratings: Duke 93.0, Gonzaga 91.5Upset probability: 41 percentPlayer to watch: Jahlil Okafor, DukeThis is shaping up to be an intriguing matchup of near-doppelgangers, as Duke and Gonzaga are practically identical in terms of their offensive and defensive prowess. The Blue Devils’ offense ranks 3rd nationally per KenPom.com’s ratings, while the Zags rank 4th; meanwhile, Duke ranks 27th on defense and Gonzaga ranks 30th. So it’s more than a little fitting that this pair faces off for the South’s Final Four spot.Despite their similarities, the differences in how the squads achieve their matching efficiencies might be instructive. On offense, Duke and Gonzaga shoot and draw fouls at very similar rates, but the Blue Devils are better on the glass and the Bulldogs protect the ball more effectively. Duke also has the better transition attack1According to Synergy. while Gonzaga owns an edge in low-post scoring. At the other end of the floor, Gonzaga’s advantages are in shot defense, rebounding and the transition game, while Duke is better at forcing turnovers and keeping opponents off the foul line.Since the FiveThirtyEight model considers the Bulldogs a modest underdog, it’s worth asking whether they employ enough high-variance tactics to help them “make their own luck” in this matchup — and, unfortunately, Gonzaga doesn’t play a slow pace, nor is it especially reliant on shooting 3-pointers, forcing turnovers or crashing the offensive boards. (Duke also plays a relatively safe style for a favorite, with an above-average pace, good offensive rebounding and no overreliance on long-distance shooting or takeaways.)Still, with their big, experienced roster, the Zags have a reasonably good chance of earning their first-ever Final Four bid. Somewhat surprisingly, they’ve only visited the Regional Final once before, and that was as a heavy underdog against UConn in 1999. This time, they’re one of college basketball’s upper-echelon programs — but will it be enough against Jahlil Okafor and the Blue Devils?