The four plays that shaped the College Football Playoff

— -- Sometimes, it's the most subtle of plays that make the difference in a championship season.

Other times, those plays radiate like a house all lit up for Christmas.

Three of the four teams in this year's College Football Playoff -- Clemson, Michigan State and Oklahoma -- had defining plays that are pretty easy to pick out. It wasn't nearly as obvious with Alabama, which won most of its games by comfortable margins.

Here's a look back at the four plays most responsible for Alabama, Clemson, Michigan State and Oklahoma being a part of this year's playoff party:

ALABAMA

A cynic might suggest that the play most responsible for Alabama being back in the playoff for the second straight year didn't even involve the Crimson Tide. Without the miracle fourth-and-25 lateral (on a bounce, no less) in overtime, Arkansas doesn't go on to beat Ole Miss 53-52. And if Ole Miss doesn't lose that game, the Rebels would have been in the SEC championship game -- and not the Tide. Who knows what the selection committee would have done in that scenario?

Either way, Alabama was the last one standing in the SEC and made more than a few plays of its own to set up its Dec. 31 matchup with Michigan State in the Goodyear Cotton Bowl Classic.

None of those plays were more critical than freshman receiver Calvin Ridley going skyward to pull in a 15-yard catch on a third-and-6 play in the come-from-behind 19-14 win over Tennessee on Oct. 24. Granted, Alabama didn't have many close games this season. But in this slugfest, the Vols had just gone ahead 14-13 with 5:49 to play. And having lost to Ole Miss a month earlier in Bryant-Denny Stadium, the Tide's championship hopes were flickering if they couldn't answer.

Sophomore ArDarius Stewart had already pulled in one 50-50 ball, a leaping 29-yard grab on the second play of the drive. But facing third-and-6 from the Tennessee 40 with just under four minutes to play, Alabama needed the passing game to come through again. Ridley, who led the Tide with 75 catches this season, turned and showed off his hops on the play. Tennessee cornerback Cameron Sutton, known for his aggressive coverage, was in good position. But Ridley soared about a foot higher than Sutton to gather in the ball on the Alabama sideline and held on for the first down. Three plays later, Derrick Henry romped 14 yards for the game-winning touchdown.

It's true that Ridley's one-handed catch to set up the go-ahead touchdown against Florida in the SEC championship game was more spectacular, but his leaping grab in the final minutes against the Vols was more important.

CLEMSON

For much of Clemson's 24-22 win over Notre Dame on Oct. 3, the rain, thanks to a whipping wind, was coming down sideways at Memorial Stadium. And for the first three quarters, the Irish wilted in the nasty conditions. They turned the ball over, missed tackles and found themselves trailing 21-3 entering the fourth quarter.

But DeShone Kizer brought Notre Dame back in the fourth quarter, and the Irish pulled within two points with seven seconds to play on Kizer's 1-yard touchdown pass to Torii Hunter Jr. in the corner of the end zone. After the game, the Clemson defenders insisted they knew what was coming on the two-point conversion attempt -- some type of quarterback run-pass option. That's exactly what they saw, as Kizer rolled down the right side of the line and kept the ball. He never had a chance; Clemson tackle Carlos Watkins blew up the blocking from the outset. Defensive end Kevin Dodd did an excellent job fighting off the Notre Dame tight end and got a hand on Kizer's legs, and linebacker Ben Boulware came darting in to fill the hole in what was a swarm of orange smothering Kizer.

Interestingly enough, Notre Dame chose to go right on the play and not left behind star tackle Ronnie Stanley, but Clemson's Shaq Lawson was also on that side and had already racked up 3.5 tackles for loss in the game. What's more, the Irish would have just needed to kick the extra point to tie the game had coach Brian Kelly not opted to go for two (and failing) after making it 21-9 early in the fourth quarter.

Notre Dame piled up 220 yards of total offense in the fourth quarter and kept the Clemson defense on its heels for most of those final 15 minutes, but the Tigers made a stand when they needed to.

"We're big on character," Clemson linebacker B.J. Goodson said. "That was a moment of truth, and we came through."

It has been that way for 13 straight games now.

MICHIGAN STATE

The Miracle in Ann Arbor made Jalen Watts-Jackson a hero for eternity in the annals of Michigan State football. It also left him with a dislocated and fractured left hip and a long, painful road to recovery. Watts-Jackson just recently started walking again on his own without the aid of crutches or a walker. He won't be able to play football again until fall camp in August, and while he'll only be able to watch from the sideline in the Goodyear Cotton Bowl Classic against Alabama, he's the one who made it all possible on Oct. 17 in the Big House.

Watts-Jackson, a redshirt freshman who made his biggest mark on special teams this season, was in the right place at the right time when Michigan punter Blake O'Neill mishandled the snap in the final seconds. The game, for all intents and purposes, was over. But when O'Neill still tried to punt the ball after dropping it, he was hit by Grayson Miller and Matt Morrissey, and Watts-Jackson plucked the ball out of midair. He raced 38 yards for a touchdown on the final play of the game, with an escort by Jermaine Edmondson, and the Spartans recorded an improbable 27-23 victory.

Watts-Jackson remembers Michigan State coach Mark Dantonio being calm on the sideline after the defense forced a three-and-out, but only 10 seconds remained and the Spartans were out of timeouts. The plan was to rush all 11, even though one of the Michigan State players lined up wide on the Michigan gunner. Watts-Jackson had 6-foot-6, 331-pound Michigan lineman Ben Braden blocking him. Watts-Jackson's job was to keep Braden from getting to teammate T.J. Harrell, who was supposed to be the block guy.

"I didn't even see the ball get dropped," Watts-Jackson said. "The first time I saw the ball was when it was in the air. I grabbed it and ran. It was crazy. I was thinking it was only 10 or 15 yards. I didn't know it was 38 yards. I just knew I had to score or we were going to lose."

The pain was so intense that Watts-Jackson said he was initially in shock after scoring while his teammates celebrated wildly. All he could do was lie there in the end zone until Michigan State's medical personnel placed him on a stretcher and drove him to the hospital, where he would have surgery the next day.

"You never want to get hurt," Watts-Jackson said. "But if that's what it took, I'm just glad I was there for my team and that they could cash in on it."

OKLAHOMA

The Sooners scored 30 or more points in winning seven in a row following their loss to Texas and erupted for 44 or more points in six of those seven wins, but it was a defensive gem that made the College Football Playoff a reality.

Defensive coordinator Mike Stoops said it ranked up there with some of the "great plays we've had," and the more you watch Steven Parker come flying in to bat down TCU quarterback Bram Kohlhausen's two-point conversion pass, the better the play becomes.

"He looked like [he] could've dunked it on a 12-foot rim," Oklahoma coach Bob Stoops said.

And even more impressive, Parker had only a split-second to react. Was he going to stick on TCU running back Shaun Nixon, who was running a corner route in the end zone, or was he going to attack Kohlhausen, who was scrambling right and toward the end zone? Parker decided to go after Kohlhausen, and on a dead sprint, he timed his leap perfectly, extended his arms and swatted down the pass with 51 seconds remaining to preserve a harrowing 30-29 win for Oklahoma on Nov. 21.

Parker, a sophomore safety, said he wasn't going to sit back in coverage and give Kohlhausen a chance to run the ball in. Of course, that meant leaving his man open. The Horned Frogs had already scored 16 unanswered points after trailing 23-7 at the half, and the momentum was clearly on TCU's side. It's one of the main reasons TCU coach Gary Patterson decided to go for the win instead of kicking the extra point and playing for overtime. Patterson also didn't want to put his team in a position where it might have to play multiple overtimes and then have a short week to get ready for Baylor. The Horned Frogs were already playing without star quarterback Trevone Boykin.

Similarly, the Sooners were without their star quarterback, Baker Mayfield, who suffered a concussion and didn't play in the second half. So with the offense sputtering -- and OU's playoff hopes teetering -- Parker took matters into his own hands and went on the offensive in one of those go-for-broke plays all teams have to make somewhere along the way if they're going to win a championship.