Alabama is a healthy favorite to reach the College Football Playoff, and the group of potential challengers is already becoming clear.

The SEC finds itself in terrific position to swipe two CFP spots for the second straight year. Notre Dame has joined the chase, and the Big 12 is taking a pair of undefeated teams into October.

Meanwhile, the ACC, Big Ten and Pac-12 are each running thin on top-tier contenders. The upcoming month could effectively end the dreams of a CFP representative for at least one league. That's great news for UCF, which is quietly hanging around once again.

Below, we'll look at whether each of the Top 20 teams in the latest Associated Press poll should be taken seriously as a playoff contender.

SEC Unbeatens

Alabama Crimson Tide: How much Alabama stock can I buy? Give me everything you can, please. Not only does Nick Saban's team have its customarily terrific defense, but sophomore QB Tua Tagovailoa has made the Tide into an offensive juggernaut. Whether Alabama finishes 12-1 or 13-0, this is a playoff team. BUY.

Georgia Bulldogs: Though Kirby Smart's squad needed to replace several key contributors on defense, it ended September tied for ninth nationally in yards per play allowed. An upcoming four-game stretch with LSU, Florida, Kentucky and Auburn is brutal, but going even 3-1 against that slate would keep the Bulldogs as contenders. We expect that. BUY.

Kentucky Wildcats: We did not see this coming. We do not see this continuing, although it's more a product of believing in Georgia to win this November clash than doubting Kentucky. Still, there is real 10-win potential from this upstart Wildcats squad. SELL.

LSU Tigers: QB Joe Burrow recently put together the best performance of his career, but LSU's offense has been inconsistent at best. Unless the Tigers manage to survive both Georgia and Alabama—don't count on it, since the running game will likely disappear in those matchups—their future doesn't include the CFP. SELL.

Other Undefeated Top 10 Teams

Clemson Tigers: Clemson's defense isn't the impenetrable force it was expected to be, and freshman quarterback Trevor Lawrence isn't perfect. But take a look at the schedule: Where do you find two losses, particularly if Clemson wins at home against NC State? Believe in the Tigers. BUY.

Notre Dame Fighting Irish: Notre Dame scuffled its way to an unimpressive 3-0 record before notching two dominant wins. Road trips to Virginia Tech, Northwestern and USC will likely shape the Irish's level of success, and those don't scare us off. Whether they're a title contender is a different question, but reaching the CFP is doable. BUY.

Oklahoma Sooners: Baker Mayfield twice set Football Bowl Subdivision records in efficiency, and Kyler Murray is currently crushing Mayfield's mark. As long as he's healthy, the Sooners can outscore any offense and atone for its own defensive shortcomings. BUY.

West Virginia Mountaineers: Traveling to Iowa State, Texas and Oklahoma State in addition to home dates with TCU and Oklahoma is brutal. West Virginia has an elite offense, but Will Grier still has a lingering tendency to force passes in tight situations. That's eventually going to haunt the Mountaineers. SELL.

Top 20 Teams in the Big Ten

Michigan Wolverines: The nation's stingiest team in yards per play allowed, Michigan can lean heavily on its defense. But the primary issue hasn't changed: Can the offense do enough? Getting a positive answer to that question against each of Wisconsin, Michigan State, Penn State and Ohio State is improbable. A second loss would—and will—doom the Wolverines. SELL.

Michigan State Spartans: Dual-threat quarterback Brian Lewerke hasn't made the expected leap in his development. Michigan State avoids Wisconsin in crossover play and boasts a tremendous run defense, but the Spartans aren't getting past Penn State, Michigan and Ohio State with this offense. SELL.

Ohio State Buckeyes: Ohio State has already navigated TCU and Penn State away from Columbus. Plus, the Buckeyes own at least a 74 percent chance to win each of their remaining games, per ESPN's Football Power Index. Even a one-loss Ohio State will receive plenty of praise from the CFP committee, especially if TCU and Penn State are Top 25 teams in November. BUY.

Penn State Nittany Lions: The collapse at home against Ohio State stung the CFP chances of James Franklin's team. Still, the Nittany Lions host each of Michigan State, Iowa and Wisconsin while only traveling to Michigan. Given how Trace McSorley performed opposite the Buckeyes, counting out the Lions seems unwise. They'll need SEC and Pac-12 teams to help them out by losing, but Penn State remains a threat. BUY.

Wisconsin Badgers: 2018 is the same story as 2017 in Madison. The Badgers have a championship-worthy defense, but can the offense complement that strength when it matters most? BYU already took advantage of the weakness, and it's bound to be a problem during road trips to Michigan, Northwestern and Penn State. SELL.  

Central Florida Knights

Last season, 15 of the AP Top 25 teams held an undefeated record in Week 6 when UCF entered the poll. This year, that number is 12—which is also the Knights' AP ranking as of now.

Keep winning, and they'll have a chance.

Dual-threat quarterback McKenzie Milton is once again shredding defenses, helping the Knights rank seventh in scoring and third in yards per game during September. Plus, the second tier of the American Athletic Conference isn't as threatening as it was in 2017.

But without a marquee nonconference victory on the schedule—Pitt probably won't sway the committee much and FAU is slumping—the Knights are at the mercy of a widespread power-conference collapse.

Is it fair? No. Is it reality? Despite our objections, it sure feels that way. 

Verdict: SELL

One-Loss Top-20 Teams

Auburn Tigers: Auburn has registered less than four yards per rushing attempt in four of its first five games. That is a hugely concerning trend despite the strength of the defense, which can't be expected to bail out the Tigers against both Georgia and Alabama to avoid a second loss in 2018. SELL.

Miami Hurricanes: While the switch from Malik Rosier to N'Kosi Perry at quarterback has enormous long-term benefits and better complements a tenacious defense, a road-heavy October and November is a problem. Can the 4-1 Hurricanes avoid a dreadful road loss with a freshman running the offense? The safe bet is no. SELL.

Oregon Ducks: We'll know the final answer after Oregon's next game. Following a bye in Week 6, the Ducks host Washington. If they can spring the upset, road trips to Washington State and Utah would be the biggest remaining obstacles. However, a loss to UW would drop Oregon to the dreaded two-loss zone, and the absence of a marquee victory would eliminate the Ducks. SELL.

Stanford Cardinal: Entering the season, Stanford was a potential CFP threat thanks to an elite offensive line and superstar running back. Neither of those have showed up. It's difficult to see the Cardinal avoiding another loss unless that changes rapidly. SELL.

Texas Longhorns: Sam Ehlinger clearly has an improved command of the system. The Longhorns probably have the best defense in the Big 12, too. But our answer changes dramatically because of the season-opening loss to Maryland. If Texas was undefeated, it would have had a chance at making it to the CFP. But rattling off a 12-game winning streak, including the Big 12 title, is too much to ask from an offense that lacks explosiveness. SELL.

Washington Huskies: This defense will travel. The ever-present question is whether Jake Browning and the offense will do the same. Upcoming games against Oregon, Colorado and Stanford will be challenging, but only the trip to Oregon seems truly concerning. Washington should be able to throw efficiently against the Ducks, though. BUY.

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