Conference races start to heat up

— -- Welcome to Showdown Saturday.

The path to the College Football Playoff begins with each conference race, and Week 7 features several Power 5 games that will show some separation in the league standings. Here's a look at the most important conference matchups this week, ranked in order from the biggest impact on the playoff picture:

1. Michigan State at Michigan

Who needs it more: Michigan. Michigan has gone from long shot to dark horse to favorite in a span of six weeks. ESPN's Football Power Index favors the Wolverines in each of their remaining games -- including Saturday against the Spartans and on Nov. 28 against Ohio State. If Michigan can win out, it would have four wins over ranked opponents, including Northwestern and the league title game. It can't afford another loss, though, after the season opener to Utah. Michigan State doesn't play Northwestern, and the win over Oregon has since been devalued, so the Spartans have little margin for error. Should they lose this one, they'd need to win out, as well as the Big Ten, to keep their playoff hopes alive.

2. Alabama at Texas A&M

Who needs it more: Alabama. The pressure is on the Crimson Tide, who already have an SEC West loss to Ole Miss. Another division loss and the Tide would need some serious help to get into the SEC title game. The Aggies, meanwhile, remain undefeated but haven't gotten much credit for their success. Their best wins are against Arizona State and Mississippi State, teams that are no longer ranked. A win over the Tide could boost A&M into top-four consideration, but it also depends on what happens in the Florida-LSU game.

3. Florida at LSU

Who needs it more: Even. With both teams still undefeated, this isn't a make-or-break game for either program's playoff hopes, but the winner will get a gold star on its résumé. This game features the top SEC team in each division, but the Gators have the most impressive record in the nation, according to ESPN's strength of record metric. Based on whom the Gators played and where they played them, an average Top 25 team would have a 16 percent chance of starting 6-0 against Florida's schedule. ESPN's FPI favors LSU on Saturday, but if Florida can pull off the road win with backup quarterback Treon Harris, the Gators will prove they're still a contender in spite of the NCAA suspension to starting QB  Will Grier.

4. Penn State at Ohio State

Who needs it more: Ohio State. The defending national champion simply can't afford a home loss to an unranked opponent when it has won in unconvincing fashion the past six weeks. The Buckeyes have been tied or trailed in the second half of four of their six games. They're the only undefeated team with a negative turnover margin and have had to share the spotlight with a surging Michigan team. Ohio State still has to play Michigan State and Michigan. It certainly can't afford to trip up now, and it shouldn't. ESPN's FPI gives Ohio State an 87 percent chance to win -- which is why this game is so low on the list.

5. Iowa at Northwestern

Who needs it more: Iowa. If the Hawkeyes lose this one, they'll also lose the head-to-head tiebreaker in the West Division if both teams finish with one league loss. They are undefeated, but they're not getting much credit for it in spite of quality wins against Pitt and Wisconsin. Of course, they also beat FCS opponent Illinois State, and 0-5 North Texas, which has since fired its head coach. In spite of the win over Stanford, it's hard to see Northwestern getting into the playoff conversation after the loss to Michigan. It would have to win out AND upset a highly ranked playoff contender from the East Division in the league title game. As long as Iowa is undefeated, it has a shot.

Thursday Thought

As teams get into the heart of conference play, keep in mind the importance of common opponents. When two teams have similar résumés, the selection committee will look to "comparative outcomes of common opponents" as part of its criteria for evaluating teams. Ohio State and Michigan will both play Penn State, for example, and they have both played Maryland. Until the head-to-head result becomes a tiebreaker, common opponents are another way for the committee to evaluate similar teams.

Superlatives

Player in the spotlight: Florida QB Treon Harris. Starter Will Grier has been suspended by the NCAA, and Harris will start against LSU. Harris started the final six games of 2014 and the opener this season. With the benefit of a stingy defense on his side, Harris doesn't have to be a superhero, but he can't be the kryptonite, either.

Don't forget about: The ACC. Clemson and Florida State are still undefeated and should stay that way after playing home games against Boston College and Louisville, respectively. Clemson leads the nation in ESPN's game control metric and is No. 2 in strength of record, meaning an average top 25 team would have a 25 percent chance of going 5-0 against Clemson's schedule.

Under the radar: Oklahoma's playoff chances. The Sooners didn't look good in their loss to Texas, but they still have to play Baylor, TCU and Oklahoma State -- three ranked teams that are currently undefeated. OU needs to bounce back this week against Kansas State to even have a shot;  the Sooners haven't lost back-to-back regular-season games since 1999, a span of 34 straight wins following losses.

Cupcake game: UCF at Temple. The undefeated Owls are soaring and UCF has hit rock bottom. George O'Leary announced this week he was resigning as the Knights' interim athletic director, but he's still the coach of an 0-6 program that suffered a home loss to FCS Furman and an embarrassing loss to UConn.

Upset watch: Ole Miss at Memphis. Memphis has won 12 straight, and postseason implications are on the line for both teams. Memphis is fighting for a spot in a New Year's Six Bowl as the highest-ranked Group of 5 champion, and Ole Miss can't afford to lose this game and get to the playoff.

Matchup to watch: Michigan's defense against Michigan State's offense. The Wolverines have three straight shutouts but have yet to face a team ranked in the top 25 in offensive efficiency. Michigan State QB Connor Cook is No. 9 in Total QBR, and the Spartans lead the league in offensive efficiency.

Can't-miss game: Florida at LSU. The Gators have been one of the biggest surprises of the season and are a front-runner to win the SEC, but can they keep up their success without Grier? If they can, the Gators should be considered one of the top four teams in the country.

Games of the week

Alabama at Texas A&M (CBS, 3:30 p.m. ET)
Pregame matchup quality: 95.5
? Texas A&M: 56 percent predicted win percentage (2.0 predicted point differential)
? Texas A&M and Alabama are two of four teams that rank in the top 10 in strength of record, FPI and game control

USC at Notre Dame (NBC, 7:30 p.m. ET)
Pregame matchup quality: 94.4
? Notre Dame: 55 percent predicted win percentage (1.8 predicted point differential)
? Notre Dame and USC rank 10th and 11th, respectively, in offensive efficiency

Florida at LSU (ESPN, 7 p.m. ET)
Pregame matchup quality: 90.1
? LSU: 63 percent predicted win percentage (4.7 predicted point differential)
? LSU ranks seventh in offensive efficiency; Florida ranks sixth in defensive efficiency

West Virginia at Baylor (Fox, noon ET)
Pregame matchup quality: 85.4
? Baylor: 90 percent predicted win percentage (18.9 predicted point differential)
? West Virginia: Plus-9 turnover margin in wins, minus-4 turnover margin in losses

-- ESPN Stats & Information