To paraphrase Julius Caesar, all of the college basketball season is divided into three parts.

The opening third, the non-conference portion with a number of holiday tournaments and tune-up games for the sport’s top-tier programs, is concluded. The second part, regular-season conference play, is now well underway, and early returns point to a whole lot of uncertainty when we reach the third segment, in which March Madness will live up to its name and then some.

Already this week in men’s college hoops, four of the top five teams and six of the top 11 have taken a loss. Two of those are now set to square off in Saturday’s headliner in our inaugural edition of the Starting Five.

No. 9 Oklahoma at No. 3 Kansas, Saturday, 2 p.m., ESPN+

Yes, you’ll have to stream this one, but it might be worth the effort. The intensity level should definitely be high with both teams in need of a bounce-back performance. The Jayhawks squandered a big lead thanks mainly to a spate of turnovers Wednesday night in a loss at Central Florida, while the Sooners couldn’t overcome several long scoring droughts at TCU. Oklahoma’s scoring balance, with eight players averaging at least six points, and strong team defense could pose a tough matchup for KU. The Jayhawks’ long-range shooting can also be spotty, though big man Hunter Dickinson can score in a variety of ways.

No. 2 Houston at TCU, Saturday,  6 p.m., ESPN

The Horned Frogs, meanwhile, don’t get long to savor their Oklahoma win with an angry pack of Cougars coming to Fort Worth. Houston’s first taste of life on the road in the Big 12 resulted in defeat at Iowa State as leading scorer L.J. Cryer was held to just five points. The 27-point performance turned in by TCU’s Emanuel Miller in the Oklahoma win undoubtedly got the attention of the Cougars’ Jamal Shead, whose 2.3 steals per game lead the relentless defensive effort that is a hallmark of Kelvin Sampson coached teams.

No. 5 Tennessee at Georgia, Saturday, noon, ESPN2

Despite a couple of losses at a star-studded tournament in Hawaii back in November, the Volunteers had worked their way back into the top five, opening SEC play with a 32-point demolition of previously unbeaten Mississippi. But Wednesday’s 77-72 setback at Mississippi State was a reminder that road life in any conference is never easy. Now Tennessee must head to Athens, where the league’s other Bulldogs are riding a 10-game winning streak. Georgia is not a big team but gets production from a lot of back-court contributors. Finding open looks against the Vols’ notoriously stingy perimeter defense, however, might still be a challenge.

Northwestern at No. 15 Wisconsin, Saturday, noon, BTN

While Purdue was topping the polls for the past month, the Boilermakers dropped a second Big Ten road game this week and find themselves down the pecking order in the standings. The Badgers, meanwhile, have climbed to the head of the class, off to a 4-0 league start including Wednesday’s tough victory at Ohio State in a back-and-forth affair. They return home to Madison to take on the Wildcats, who were responsible for one of those takedowns of Purdue but also have a terrible result against Chicago State on their resume. A high-end road victory in the Kohl Center would help, which will likely require a lights-out day from the arc. Northwestern does connect at a respectable 37.7% clip from three-point range, but the ‘Cats be at a disadvantage on the glass against Wisconsin’s frontcourt if the treys aren’t falling.

St. John’s at No. 20 Creighton, Saturday, 1 p.m., Fox

Rick Pitino as expected has wasted little time making the Red Storm relevant again in the hotly-contested Big East, entering the weekend with a share of the league lead after wins against Villanova and Providence. They head west to Omaha, where the Bluejays have rattled off three wins in a row after starting 0-2 in the conference. Though Creighton is still known as a perimeter team heavily reliant on making jumpers, veteran big man Ryan Kalkbrenner is an effective rim protector averaging 2.4 blocks. His battle in the paint with the Red Storm’s Joel Soriano should be worth watching.