Stanford senior Conrad Ukropina, right, celebrates his winning field goal against Notre Dame. (Ezra Shaw/Getty Images)

Suddenly, three months of little plays here and big mood swings there, all across the country, distilled to one 193-pound football player who pretty much resembles many a non-football Stanford student. As a senior from Pasadena, Calif., named Conrad Ukropina readied for a 45-yard field-goal attempt on Saturday evening in the California cold — a tad icier via a Notre Dame timeout — he held in his right foot some large variables.

Six seconds remained. Either the nation and its craziest sport would have a loud discussion involving Notre Dame and the College Football Playoff or it would not. Either Notre Dame would make off with an 11-1 record and a playoff argument and a one-point win earned through an 88-yard drive with the outstanding young quarterback DeShone Kizer, who didn’t even start the season, or it would fall away to 10-2 by a score of 38-36. Either the playoff committee’s task would thicken or it would simplify.

Well, from field level, Ukropina’s strike looked cocksure, aggressive, almost menacing. He crushed his winner with such vengeance that it seemed to scream through the top of the posts. Then, as Stanford players began a mad scramble to a happy scrum over their own 10-2 record, many of the 51,424 streamed onto the field. Soon, Ukropina stood surrounded by huggers and selfie-takers.

Maybe he even knew some of them.

“With Conrad out there,” senior quarterback Kevin Hogan (Gonzaga High) said, “I had no doubt.”

Somewhere in that mass on the field, Notre Dame exited both Stanford Stadium and the playoff picture. “Like I told our team, it’s tough to win games,” Irish Coach Brian Kelly said. “Winning’s hard. . . . The reality is we’re two plays away from being undefeated and being the number one team in the country. One play at Clemson and one play here at Stanford.”

Ranked No. 6 most recently on the College Football Playoff list, Notre Dame has lost only by 24-22 at Clemson, which ranks No. 1 on the way to the ACC Championship Game, and by 38-36 at Stanford, which ranks No. 9 on the way to the Pacific-12 Championship Game. The Irish did this despite an unusual raft of injuries, what Kelly called “some catastrophic injuries . . . and we’re talking about across-the-board here.”

Asked how he processes such nearness, Kelly said matter-of-factly, “You really don’t.”

The maddest sport had struck again.

Stanford, after all, looked doomed when Kizer rolled left and muscled into the end zone from the 2-yard line with 30 seconds left for a 36-35 lead following the extra point. Then it won largely because Hogan hit Devon Cajuste with a flawlessly timed 27-yard pass over the middle to the Notre Dame 30-yard line with nine seconds left. It won as Coach David Shaw said of Hogan, in his final home game, “I challenge anybody to find a better two-minute quarterback in the nation,” calling him “so mature” and “so confident” and “such a great leader.”

Hogan’s one incompletion on the frantic, final, 45-yard march to Ukropina’s field goal was only his fourth of the game, among 21 attempts. He passed for 269 yards. He left with joy — “It was the best,” he said — to override that of his previous home game, a 38-36 loss to Oregon on Nov. 14 in which Hogan and Stanford suffered two shocking, drive-quashing, fourth-quarter fumbled snaps. If that loss left Stanford on the outskirts of the chase to the four-team playoff with two losses, the team that played Notre Dame wasn't wallowing and didn’t act demoralized.

With Hogan so proficient and the national all-purpose-yardage leader Christian McCaffrey rushing for 94 yards, Stanford assembled five touchdown drives of 75 yards or longer. That offset Notre Dame’s thrilling scoring capacities, which included a 93-yard kickoff return from C.J. Sanders, a 73-yard touchdown pass from Kizer to the fantastic Will Fuller and a 62-yard touchdown run from Josh Adams, the freshman brought in because of two major injuries at running back.

Adams gained a Notre Dame freshman-record 168 yards on 18 carries, Kizer 128 on 16. For the 12th game out of 12, Notre Dame looked like it could beat just about anybody. On its 88-yard drive for the go-ahead touchdown, it took 15 gritty plays, including a third-down pass where Kizer faced horrid pressure and a fourth and one from the Stanford 8-yard line with the clock ticking to 41 seconds at the snap.

After all of that, there could have been a long, loud discussion, perhaps pitting Notre Dame against Oklahoma for playoff worthiness. “The fact of the matter is, we’re not going to get that chance,” Kelly said.

That grew clear when a 193-pounder from Pasadena swept his leg forward.

In a way, in a berserk season, that figured.