In the first four seasons of the College Football Playoff era, 30 teams cracked the Top Four at some point in the rankings.

In 2018, that number is only five.

After the initial poll in 2014 through 2017, a new program entered the Top Four in 14 of the next 21 rankings. This year has featured a single change over the subsequent three weeks.

Kinda anticlimactic, huh?

No. 1 Alabama and No. 2 Clemson topped 2018's first ranking and haven't moved from their respective spots. Notre Dame opened at No. 4 and moved up when Alabama bounced LSU. Michigan replaced LSU and has rounded out the Top Four in three straight weeks.

The lack of movement isn't a concern. No Top Four program has lost except for LSU, and no recent victory by a top-ranked program merited a significant boost.

Rivalry Week will be different.

No. 10 Ohio State will challenge No. 4 Michigan. No. 6 Oklahoma will travel to No. 13 West Virginia. No. 8 Washington State will host No. 16 Washington.

That trio of Top 25 matchups will have a substantial impact on next week's rankings.

Notre Dame will be guaranteed a CFP spot with a win Saturday. The Fighting Irish are 10.5-point favorites against USC, per OddsShark, so Brian Kelly's club will likely clinch a playoff berth.

Will the committee be willing to reward a dominant Michigan team in the final rankings despite a head-to-head loss to Notre Dame? That won't matter unless the Wolverines snap a six-game skid against Ohio State.

If the Buckeyes win, they're certain to jump in the rankings—at least above LSU, regardless of its result at Texas A&M. How would Ohio State compare to Georgia and Oklahoma, though? Might a marquee win over Michigan vault the Buckeyes past those one-loss squads?

Meanwhile, Oklahoma must navigate a trip to West Virginia. Would a Top 15 road victory push the sixth-ranked Sooners above fifth-ranked Georgia?

Washington State remained stuck behind LSU for the third straight week. It hasn't defeated Washington since 2012, but it could add a quality win to the resume with a victory over its in-state rival.

UCF put together its best performance of the season in its blowout of Cincinnati. The Knights captured the committee's attention, moved up to No. 9 and head to South Florida this week.

Take a breath. There's a lot going on.

The favorites may hold serve as championship week approaches. Michigan, Oklahoma and Washington State could each win, so there's no guarantee the order will change.

But there will be an effect.

For the first weekend since Alabama thrashed LSU, these upcoming games may have a major impact on the committee's discussions. Putting together the rankings next Tuesday won't be as simple.

Washington State's Uphill Climb

Two weeks ago, the Notebook wondered whether Washington State has a realistic chance to make the playoff. That opinion hasn't changed, but the outlook is clearer.

Alabama and Clemson remain obvious favorites for two spots. Notre Dame is a victory over USC from securing its place. That leaves one CFP berth for a one-loss Big Ten champion, a one-loss Big 12 winner or Washington State.

No matter whether Michigan or Ohio State wins Saturday, Wazzu is rooting for Northwestern in the Big Ten Championship Game.

If West Virginia defeats Oklahoma, the Big 12 is out. Should the Sooners win, however, the Cougs will be pulling for Texas (or West Virginia, if Kansas somehow upends Texas) in the title game.

But that combination is unlikely at best, and without it, WSU isn't joining the Top Four. The committee has consistently kept Michigan, Ohio State and Oklahoma higher, and they each have a chance to improve their resumes this weekend.

Washington State's comprehensive dismantling of Arizona gave the committee something new to consider, but it still wasn't enough to lift the Cougs into an advantageous spot.

Showdown in the Mountain West

Central Florida has always been the Group of Five team to beat. After a 38-13 obliteration of Cincinnati last week, No. 9 UCF became the first Group of Five program to earn a Top 10 CFP ranking.

The Knights are likely headed toward another undefeated record. But what if they lost?

The committee's attention would quickly shift to No. 21 Utah State or No. 23 Boise State, pending Saturday's result between the teams.

Utah State—led by Matt Wells, who will be popular on the coaching carousel this offseason—has gone a perfect 10-0 since taking Michigan State to the wire in August. The Aggies rank second nationally in scoring offense and are tied for 13th in tackles for loss.

Boise State's steady offense has atoned for the program's least efficient defense of this century. Still, the Broncos have limited each of their last three opponents to 17 points or less—including then-No. 23 Fresno State in another pivotal game.

The winner isn't assured of New Year's Six attention, but any slip from UCF would create an opportunity for Utah State or Boise State.

CFP Quarterbacks Will Be a Fresh Group

Sixteen teams have reached the College Football Playoff in its brief existence. Thus far, at least two quarterbacks every season had at least a year of previous starting experience.

That's likely to change in 2018.

Although Tua Tagovailoa became a star when he engineered Alabama's comeback in the national championship, he didn't officially start until September. Trevor Lawrence replaced Kelly Bryant at Clemson one-third of the way through the regular season.

Ian Book (Notre Dame), Dwayne Haskins (Ohio State) and Kyler Murray (Oklahoma) are new starters. Shea Patterson (Michigan) and Gardner Minshew (Washington State) are experienced, but they transferred and are first-year starters at their current school.

Georgia's Jake Fromm is the only quarterback on a CFP-contending team who started a majority of the 2017 season and remains the No. 1 guy for the same program.

Stats from cfbstats.com or B/R research. Quotes obtained firsthand unless otherwise noted. Follow Bleacher Report CFB Writer David Kenyon on Twitter @Kenyon19_BR.