As college football's regular season heads into its stretch run, plenty of intriguing plotlines are developing each week.

Revenge motives. Playoff implications. Clashes of style. Matchups of two-way players.

Here are some of the top things to watch this week:

BUCKEYES' BIG CHANCE: No. 13 Ohio State continues to pay dearly for its early-season home loss to Virginia Tech, which has gone 2-5 since. The price of that defeat is evident from the Buckeyes' No. 14 position in the College Football Playoff rankings.

Ohio State can make a statement to the selection committee — and earn a measure of revenge — when it travels to No. 7 Michigan State (No. 8 CFP). The Spartans beat Ohio State 34-24 in last year's Big Ten championship game to ruin the Buckeyes' national title hopes.

"After watching them on film, they're a great team," Ohio State coach Urban Meyer said. "And they stand in the way of the Big Ten championship. They stood in the way last year, and we failed."

DUELING DEFENSES: During a season in which so many big games have featured teams scoring in the 40s and 50s, Saturday's showdown between No. 4 Alabama (No. 5 CFP) and No. 14 LSU (No. 16 CFP) should offer a refreshing contrast.

Alabama has allowed just 14 points per game to rank second among all Football Bowl Subdivision teams in scoring defense. LSU ranks fourth at 15.9.

Both teams expect a physical game.

"They're definitely a physical bunch up front," Alabama defensive lineman Jonathan Allen said. "They play similar to our playing style. As a defense and defensive line, we look forward to that smashmouth football."

BIG 12 BATTLE: As expected, the Big 12's premier game of the season takes place this week.

The surprise is that the headline attraction isn't No. 10 Baylor (No. 12 CFP) at No. 16 Oklahoma (No. 15 CFP), though that game certainly carries plenty of weight. It's just that No. 9 Kansas State (No. 7 CFP) at No. 6 TCU (No. 6 CFP) is even bigger. Each team needs a win to boost its playoff hopes.

This clearly is the toughest remaining test for TCU, which visits Kansas and Texas and hosts Iowa State in its final three games. The road is much bumpier for Kansas State, which still must travel to No. 24 West Virginia (No. 23 CFP) and Baylor while also hosting Kansas.

CRITICAL INJURIES: No. 8 Notre Dame (No. 10 CFP) and No. 12 Mississippi (No. 11 CFP) both suffered major losses last week, though the Irish actually won their game.

Notre Dame linebacker Joe Schmidt fractured and dislocated his left ankle in a 49-35 victory over Navy, so the Irish must play the rest of the season without their leading tackler. Schmidt's injury likely forces freshman Nyles Morgan into a starting role Saturday at No. 11 Arizona State (No. 9 CFP).

Mississippi wide receiver Laquon Treadwell broke his left fibula and dislocated an ankle while attempting to score a game-winning touchdown in a 35-31 loss to No. 3 Auburn (No. 3 CFP). Treadwell instead was tackled from behind and fumbled just before reaching the end zone.

Treadwell's injury comes one week after linebacker Denzel Nkdemdiche broke a leg, knocking him out for the rest of the season.

TWO-WAY TALENTS: Two of the nation's top two-way players will be showcased when No. 18 UCLA (No. 18 CFP) visits Washington.

Washington's Shaq Thompson has scored six touchdowns — four on defense and two on offense. Thompson already was having a stellar season as a linebacker when injuries to Washington's running backs caused him to move over to offense. In his last two games, Thompson rushed for 98 yards against Arizona State and 174 yards against Colorado.

UCLA linebacker Myles Jack made 75 tackles and ran for seven touchdowns as a part-time running back last season. Although he has concentrated more on defense this year, Jack still has rushed for 71 yards on 22 carries while also producing 63 tackles.