With its 38-17 win over No. 7 Stanford on Saturday night, Notre Dame changed the College Football Playoff picture heading into October, simply by joining the discussion.

At least for now -- in this weekly snapshot college football lives by until the next upset -- Notre Dame has a 47 percent chance to reach the playoff, according to ESPN's Playoff Predictor. It's an encouraging number and sets a vastly different expectation than what accompanied the Irish's underwhelming offensive performances in wins against Ball State and Vanderbilt. The decision to start Ian Book at quarterback instead of Brandon Wimbush the past two games has not only elevated Notre Dame's offense, it has also raised the Irish's playoff hopes.

"We've got a long season ahead of us," Notre Dame coach Brian Kelly said at Saturday's postgame news conference. "So if we're going to walk out of here thinking that we just are the best team, we're going to get beat and it's going to diminish this victory. So I told our team, 'I'm proud of what you accomplished tonight, but if we don't embrace how hard this is going to be, we're climbing Mount Everest with this schedule. So take one step at a time and get ready for a tough opponent in Virginia Tech.'"

The Hokies (Saturday, 8 p.m. ET, ABC) aren't the only obstacle standing in Notre Dame's way. There's one-loss Washington, which shares Stanford as a critical opponent. There are undefeated Clemson, undefeated Oklahoma and undefeated Ohio State. There's the SEC, which still has four undefeated teams and could again place two teams in the semifinals (39 percent chance, according to ESPN's Football Power Index).

"It's all going to play out, a lot of things beyond the SEC's control," Georgia coach Kirby Smart told ESPN when asked about the league getting two teams in again. "It's just too much that we don't know about."

Here's what we do know: Only a handful of teams stood a chance at the beginning of the season -- and the field has already shrunk. Fourteen teams had at least a 1 percent chance to win the College Football Playoff in August. We're now down to nine.

Many of the past 16 semifinalists have these things in common: a regular-season schedule ranked in the top 55; a nonconference game against a Power 5 opponent; at least two wins over ranked opponents; a head coach who has previously won a conference title; a player who finished in the top 10 of the Heisman Trophy voting; a top-four finish in ESPN's strength of record metric; a top-15 ranking in either offensive or defensive efficiency; and a ranking among the top 10 nationally in scoring margin. These are the teams that enter Week 6 with a real shot, and a look at whether they're following the trends of past semifinalists:

1. Alabama Crimson Tide

Chance to make the playoff: 75.4 percent

Chance to win the title: 32.6 percent

Trends in their favor: Alabama can check almost every box. The Tide are ranked No. 1 in offensive efficiency and No. 2 in defensive efficiency. Alabama leads the nation in points margin per game at 41.2. One of the reasons Alabama's offense is soaring is quarterback Tua Tagovailoa, who is currently leading ESPN's Heisman Watch. Thirteen of the past 16 semifinalists had a player finish in the top 10 of the Heisman voting that season. Alabama's remaining SOS is No. 38, and while Louisville hasn't been very good, the Tide can at least claim a win over a Power 5 nonconference opponent.

What's missing: Wins against ranked opponents (every past semifinalist has had at least two wins over AP-ranked teams). A top-four ranking in ESPN's strength of record metric (Alabama is currently No. 8; all 12 semifinalists over the past three seasons have been in the top four).

2. Ohio State Buckeyes

Chance to make the playoff: 74.9 percent

Chance to win the title: 22.9 percent

Trends in their favor: The Buckeyes are currently No. 1 in SOS, which means the average Top 25 team would have a 12 percent chance to start 5-0 against Ohio State's schedule. They've also got a Heisman contender, as quarterback Dwayne Haskins is No. 2 in ESPN's Heisman Watch. Ohio State is No. 5 in offensive efficiency and is tied with Georgia for fourth in scoring margin at 30.2.The Buckeyes already have two wins against ranked opponents in TCU and now Penn State. The remaining strength of schedule is No. 39.

What's missing: Not a thing, as far as past trends go.

3. Georgia Bulldogs

Chance to make the playoff: 52 percent

Chance to win the title: 13.9 percent

Trends in their favor: Georgia is No. 1 in defensive efficiency and No. 7 in offensive efficiency. It also has a coach who previously won the conference title in Kirby Smart.

What's missing: A Heisman hopeful, and the schedule. The Bulldogs are No. 6 in strength of record, which isn't bad at all, but Missouri is the only opponent they've played with a record over .500. Georgia also doesn't have any wins over ranked opponents yet, as South Carolina has dropped out of the AP poll since its loss to Georgia. The Bulldogs also haven't played a Power 5 nonconference opponent yet and won't until the Nov. 24 regular-season rivalry game against Georgia Tech.

4. Clemson Tigers

Chance to make the playoff: 56 percent

Chance to win the title: 10.8 percent

Trends in their favor: The obvious is the experience of coach Dabo Swinney and the important Power 5 road win at Texas A&M. Clemson is No. 3 in the nation in defensive efficiency.

What's missing: The superstar and the schedule. Like Georgia, Clemson doesn't have anyone currently in the Heisman Watch, and the Tigers entered this week with some uncertainty at quarterback. Starter Trevor Lawrence was injured on Saturday, and Kelly Bryant has said he will transfer. Whether either of those is a long-term issue remains to be seen. Clemson is No. 20 in scoring margin at 21.2 points per game. Clemson is No. 5 in SOR, but it hasn't defeated any ranked opponents yet, and the lone opportunity as of now is Oct. 20 against No. 23 NC State.

5. Notre Dame Fighting Irish

Chance to make the playoff: 47 percent

Chance to win the title: 6 percent

Trends in their favor: The biggest thing in Notre Dame's favor are the two wins over ranked opponents (Michigan and Stanford), and Notre Dame is currently No. 4 in SOR. The average Top 25 team would have an 18 percent chance to achieve Notre Dame's 5-0 record against the same schedule.

What's missing: Notre Dame's remaining SOS rank is No. 61, which is why the win over Stanford was so important. Virginia Tech snuck back into the rankings at No. 24 this week, but would the Hokies fall right out again if they lose at home to the Irish on Saturday? Sometimes the value of wins over "ranked" opponents can be blurry. Notre Dame hasn't cracked the top 15 in offensive (No. 31) or defensive (No. 19) efficiency yet. Notre Dame is No. 38 in scoring margin at 14 points per game. There are also only two games' worth of statistics with Book as quarterback.

6. Oklahoma Sooners

Chance to make the playoff: 32.6 percent

Chance to win the title: 5.3 percent

Trends in their favor: Offensive star power. The Sooners are No. 2 in the country in offensive efficiency, thanks in large part to Heisman-hopeful quarterback Kyler Murray, who has thrown 17 touchdowns to just two interceptions. They have the regular-season win over a Power 5 nonconference opponent, but much like Alabama's win over 2-3 Louisville, OU's win over 0-4 UCLA won't do much to impress the selection committee.

What's missing: OU doesn't have any wins against ranked opponents yet, and Army and Baylor are the only teams above .500 it has beaten. The Sooners are No. 10 in SOR, but their schedule is back-loaded with games against Top 25 teams Texas, Oklahoma State and West Virginia.

7. Penn State Nittany Lions

Chance to make the playoff: 15.9 percent

Chance to win the title: 3.3 percent

Trends in their favor: In spite of PSU's loss to Ohio State, quarterback Trace McSorley is still one of the best players in the country and remains on ESPN's Heisman Watch. The Nittany Lions are also No. 13 in offensive efficiency and No. 6 in the country in scoring margin at 28.6 points per game. They have a nonconference Power 5 win, albeit against 2-3 Pitt.

What's missing: The lead in the Big Ten East. With the loss to Ohio State, the Nittany Lions are playing from behind in the division race, but they still have the best chance of any one-loss team to make the playoff. The Nittany Lions don't have any wins over ranked opponents, but like Oklahoma, they still have plenty of opportunities to earn some in the heart of league play.

8. Washington Huskies

Chance to make the playoff: 13.6 percent

Chance to win the title: 2.1 percent

Trends in their favor: The Huskies are second to Penn State among the one-loss teams that have the best chance to still make the playoff, and their outlook could change entirely if they win out and beat Stanford along the way on Nov. 3. Washington is No. 11 in strength of record, and can still boost its case if Oregon, Colorado and Stanford all stay ranked.

What's missing: Just about everything else. Schedule. Big wins. Heisman candidate. Strength of record. Offensive and defensive efficiency. Scoring margin. While the Huskies' 35-7 win over independent BYU was impressive, they are missing the nonconference win against a Power 5 opponent because of the loss to Auburn. Of the past 16 semifinalists, 2014 Ohio State (vs. Virginia Tech) was the only team to lose its nonconference game against a Power 5 opponent. The committee will consider how far away Washington had to travel, and the loss was only by five points, but as far as what we've seen from the committee in past years, Washington's résumé doesn't stack up right now. Washington is also outside of the top 15 in both offensive and defensive efficiency, and No. 11 in SOR and No. 33 in scoring margin (17 PPG).

9. Michigan Wolverines

Chance to make the playoff: 8.1 percent

Chance to win the title: 1.1 percent

Trends in their favor: Michigan is No. 11 in defensive efficiency, and we saw that strength in its win against Northwestern.

What's missing: A head coach who has previously won a conference title. Michigan coach Jim Harbaugh is 1-5 against Michigan State and Ohio State and hasn't won the division yet. The Wolverines also don't have anyone currently in the Heisman debate. Michigan is also missing wins over ranked opponents, as it lost the chance for one in the season opener against Notre Dame. The Wolverines have a three-game stretch beginning Oct. 13 -- against No. 16 Wisconsin, No. 20 Michigan State and No. 11 Penn State -- that will define their season.

The others

It's a common theme here -- and also to be expected, considering we're entering only Week 6 -- that some of the best teams in the country are still in need of résumé-boosting wins. There are ample opportunities, especially in the Big 12, Big Ten and SEC. Two more teams that were just on the verge of making the list were LSU and West Virginia, which both have a 6.4 percent chance to make the playoff but only a 0.6 percent chance to win it all.

WVU coach Dana Holgorsen knows how difficult it is.

"Every kid is going to say two things: They're going to say they want to go to the CFP, and they want to win a national championship," he said. "I'm like, 'Well, that's all good, but you've got to get to the Big 12 championship game first.' I like goals that you can achieve as opposed to just the ultimate one. That's everybody's ultimate goal, but it's very, very unrealistic to about 98 percent of the teams out there."

Which is why we're already down to nine.