Week 4 of the college football season is underway, and it's looking like this could be the best Saturday schedule yet. After getting no games between ranked teams a week ago, this week's slate features a staggering six matchups pitting AP Top 25 squads against each other. So, expect the landscape of the college football season to come into focus by the time things wrap up in the wee hours of Sunday morning. 

The SEC showdown between No. 15 Ole Miss and No. 13 Alabama in the SEC on CBS Game of the Week features a coaching matchup between Lane Kiffin and Nick Saban, respectively, that has become one of the can't miss matchups every year. On the field, Alabama will be looking to catch an offensive spark after last week's sluggish 17-3 win over South Florida in Tampa. 

The Big Ten features two massive games -- one out-of-conference matchup and one conference showdown that will resonate throughout the league. No. 6 Ohio State will square off with No. 9 Notre Dame in South Bend, Indiana, with the loser having no margin for error in the race for the College Football Playoff. No. 7 Penn State will host No. 24 Iowa on Saturday night on CBS in a game that will provide insight into the trajectory of both Big Ten contenders. 

What should you pay attention to on Saturday? Here's a viewer's guide to help you navigate through all of the action.

All times eastern

The best games

No. 4 Florida State at Clemson -- noon on ABC, fuboTV (try for free): This was supposed to be the biggest game of the ACC season, but when the Tigers fell to No. 18 Duke in Week 1. Florida State's win over Boston College last week was a mess, but a win over Clemson would work wonders in the Seminoles' quest for the ACC title. This one will likely come down to what Tigers' coach Dabo Swinney and offensive coordinator Garrett Riley ask of quarterback Cade Klubnik. They seemed to call plays to protect him in the opener rather than letting him loose. 

No. 19 Colorado at No. 10 Oregon -- 3:30 p.m. on ABC, fuboTV (try for free): The "Deion Sanders Experience" will have its biggest test of the season when the Buffaloes tee it up against the Ducks in Eugene, Oregon in Colorado's first Pac-12 game of the season. Star wide receiver/defensive back Travis Hunter won't be available for "Coach Prime," which will make this even more of a challenge than it already was. If Colorado can knock off a top-10 team that is a legitimate CFP contender, the hype will reach ludicrous levels.

No. 22 UCLA at No. 11 Utah -- 3:30 p.m. on Fox, fuboTV (try for free): The Utes have just been hanging around the periphery of the CFP race, while the Bruins need a big win to announce their presence on the national scene with authority. The Pac-12 is known for its offenses this season, but this game features two top-tier defenses that will be a joy to watch for old-school college football fans.

No. 15 Ole Miss at No. 13 Alabama -- 3:30 p.m. on CBS, CBSSports.comCBS Sports App (Free): Will Crimson Tide quarterback Jalen Milroe thrive now that he's back as their starting quarterback? Or, will the Tide's woes continue against a Rebels squad that is capable of lighting up the scoreboard? Kiffin would love nothing more than to essentially end Saban's title chances and beef up his team's own CFP resume. Get your popcorn ready. 

No. 14 Oregon State at No. 21 Washington State -- 7 p.m. on Fox, fuboTV (try for free): Both of these teams are flying under the radar in a Pac-12 that has been dominated by talk focused on Colorado and -- to a lesser extent -- Washington, Oregon and USC. That will change Saturday night when the winner of this game launches itself into the legitimate conference title race. 

No. 6 Ohio State at No. 9 Notre Dame -- 7:30 p.m. on NBC, fuboTV (try for free): The quarterback battle here will be awesome to watch. Buckeyes quarterback Kyle McCord has established himself as a budding star, while Fighting Irish quarterback Sam Hartman has solidified himself as one of the best quarterbacks in the nation in his new home in South Bend. It's safe to say that this is the biggest game of the young season, with the loser having no margin for error for the rest of the season.

No. 24 Iowa at No. 7 Penn State -- 7:30 p.m. on CBS, CBSSports.comCBS Sports App (Free): The Hawkeyes and Nittany Lions will square off in the biggest Big Ten conference game of the young season. The Hawkeyes will be a bit banged up as they head into Beaver Stadium and will likely need a big offensive explosion to keep up with the Nittany Lions. Meanwhile, Nittany Lions quarterback Drew Allar will be facing the biggest test of his young career.

Best of the rest