As the college football season winds toward its midpoint, this is the week when pecking orders in the major conferences get determined.By now, the favorites in the power conferences are well established, but games this weekend will help sort out which teams sit just behind. Here’s a look at the key games.

NO. 23 RUTGERS (4-0) AT SOUTH FLORIDA (3-1)
(Friday, 8 p.m., ESPN2)

Friday night games are rarely worthy of the national spotlight, but that’s not the case this week. Rutgers has been building toward this moment since the arrival of coach Greg Schiano in 2001 — a nationally televised game to showcase its newly ranked program.

The Scarlet Knights, who are ranked this week for the first time in 30 years, made a breakthrough last season, going 7–5 and qualifying for the Insight Bowl. The momentum has carried over to this fall, with Rutgers winning a tight road opener at North Carolina before hammering Illinois, Ohio, and Howard to gain entry into the polls.

This game is the biggest roadblock to a potential 8–0 start for Rutgers before it plays Big East heavyweights Louisville and West Virginia in November. The Knights cannot afford to overlook South Florida, which won the first-ever meeting between the schools last season, 45–31.

When Schiano, a former Miami (Fla.) assistant, set about rebuilding the Rutgers program, he did so by recruiting heavily in Florida. Knowing that the state turns out more than enough blue-chip high school talent to feed its three elite programs (Miami, Florida, and Florida State), Schiano started bringing some of the leftover players to New Jersey. It’s the same theory on which the South Florida program is built. USF is one of four programs in the state — the others are Central Florida, Florida Atlantic, and Florida International — that have moved up to Division I-A in recent years based on the same practice of scraping up Sunshine State leftovers.

South Florida, which joined the Big East last season, gained national attention in 2005 when it stunned Louisville at home. This year, most of its best athletes are on defense, where standout linebackers Stephen Nicholas and Ben Moffitt will try to cope with the Rutgers rushing tandem of tailback Ray Rice and fullback Brian Leonard. If they can contain the Rutgers ground game, the contest will turn on the play of Knights quarterback Mike Teel, who has not yet been forced to pull out a game this season.

The pleasant surprise for Rutgers this year has been the play of its defense, which is ranked fourth nationally. It should be able to contain a South Florida offense that has managed just 31 points the last two games.

NO. 24 GEORGIA TECH (3-1) AT NO. 11 VIRGINIA TECH (4-0)
(Saturday, 3:30 p.m., ABC)

Virginia Tech is quietly undefeated and up to 11th in the AP poll, but the Hokies remain something of a mystery.They struggled to beat Cincinnati at home last week, rallying for 17 points in the fourth quarter to win, 29–17.This week, Georgia Tech comes calling, riding the confidence of a three-game winning streak that followed a season-opening home loss to Notre Dame. Worse yet for the Hokies, coach Frank Beamer has suspended two starters for disciplinary reasons.

With no dominant teams in the ACC, even the loser of this contest will remain alive for a spot in the conference title game, but both schools have bigger tests coming up. Georgia Tech has the added motivation of seeking revenge for the 51–7 beating they absorbed at the hands of the Hokies last season.

If the Yellow Jackets have an advantage in this game, it’s that they have the best player on the field in wide receiver Calvin Johnson.The junior, who is a potential top-three pick in the NFL draft if he turns pro following the season, is simply a man among boys at the collegiate level. Johnson has a rare combination of size (6-foot-4, 235 pounds), speed, and hands to dominate college defensive backs. If anything, Georgia Tech and quarterback Reggie Ball are guilty of not throwing to him enough, because even when he’s covered, Johnson has a chance to use his large body to shield defenders and make the catch.

Virginia Tech is built around the running game of Brandon Ore, its defense (seventh nationally), and Beamer’s trademark: special teams. The Hokies blocked a punt for a safety last week.

NO. 1 OHIO STATE (2-1) AT NO. 13 IOWA (4-0)
(Saturday, 8 p.m., ABC)

Saturday’s marquee game pits a pair of undefeated Big Ten teams in what could be the last true test for Ohio State before it plays Michigan in the regular season finale.The Buckeyes are coming off a 28–6 win over Penn State, a game that was far closer than the final score indicated. Penn State was within eight points in the final minutes before Ohio State returned a pair of interceptions for touchdowns to turn the contest into a rout.

Lost in the hoopla over the win was the fact that Ohio State played perhaps its worst game of the year. Other than a highlight-reel-worthy, scrambling touchdown pass from Heisman contending quarterback Troy Smith, the Buckeyes did little right on offense against a Penn State defense that was pushed around by Notre Dame.

Still, Smith has been steady and effective this year, remaining in the pocket more to get the ball into the hands of his playmaking wide receivers, Ted Ginn Jr. and Anthony Gonzalez. On defense, the Buckeyes have been dominant, allowing just 32 points in four games, including a combined 13 to Texas and Penn State.

Iowa quarterback Drew Tate, an experienced senior, is one of the nation’s most underrated passers. He has the ability to match Smith play for play and keep Iowa in the game. Ohio State has more talent top-to-bottom on the roster, but an Iowa upset before a raucous home crowd at Kinnick Stadium would not be a complete surprise.Jim Tressel’s Buckeyes certainly won’t be rattled by the atmosphere, not after shutting down Texas on the road in the season’s second week.

Mr. Levine is a regular writer for FootballOutsiders.com.