Michigan State at USC, Week 4 2025: who deserved to win?

Final

Michigan State Spartans	31
USC Trojans	45

September 20, 2025 · Los Angeles Memorial Coliseum · Closing line: USC −18.5

Replay with same day's form

Luck index +11 USC about even · −11 Michigan State

Each team’s own plays from this game, resampled into new drives 4,000 times: with the way both teams actually played, how often does this performance win? How the replay works

Ten replays. Michigan State wins 1, USC wins 9.

1 MSU 24 USC 17
2 MSU 24 USC 27
3 MSU 31 USC 37
4 MSU 24 USC 34
5 MSU 42 USC 55
6 MSU 6 USC 21
7 MSU 14 USC 34
8 MSU 6 USC 28
9 MSU 10 USC 38
10 MSU 28 USC 63

Three other ways to ask

Each answers a different question, so none of them replaces the replay above.

Before kickoff

The closing betting line, turned into a probability. What everyone knew before the game.

Same teams, fresh game

The line plus what this game showed, weighted by how much one game can tell. It stays close to the line because one game says little.

Only coin-flips re-rolled

Every kick, fumble bounce, conversion and judgment call redrawn; everything else fixed. The narrowest view of luck.

How 4,000 replays ended

Michigan State wins 11% of them, USC 89%. The line is what actually happened: USC by 14.

Actual: USC by 14 494235282114707142128354249 ← Michigan State win by USC win by →

Show as a table

Final margin in the replays	Share of replays
Michigan State by 17+	0.9%
Michigan State by 9–16	2.9%
Michigan State by 1–8	6.5%
Level after regulation	0.4%
USC by 1–8	17.3%
USC by 9–16	21.1%
USC by 17+	50.9%

Where the luck was

What the luck was worth

Every lucky and unlucky play, weighted by the moment it happened: its swing in win probability, added up by kind. A missed kick in a decided game counts for nothing; the same kick at the end of a tie game can be most of a win.

Kicks +2% USC

Pre-snap flags +1% MSU

Fumble bounces +1% MSU

All luck +1% MSU

Swings add up across a game, so in one that went back and forth they can pass 100%. On the scoreboard the same luck was worth 0.0 points to USC: the final margin was USC by 14, without the luck USC by 14. Luck shares are the fitted ones (how much of each kind is luck).

The kicks

How likely each kicker was to make that kick (his own record, the distance), and what happened.

R. Sayeri, 25 yds made · 91% expected
M. Connington, 29 yds made · 88% expected
M. Connington, 56 yds missed · 45% expected

Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Michigan State 3 for 10 yards, USC 10 for 79 yards

Every accepted flag, in order, and what it did to the helped team’s chance of winning at that moment, including any play it wiped out (points on the scoreboard in grey). A flag in a decided game is worth nothing; one at the turn of a close game can be worth most of a win. Judgment calls count toward luck, pre-snap fouls mostly don’t. How calls are valued

When	Flag	Win probability for
Q1 11:26	Block Below the Waist on Michigan State, 0 yards	+1% USC +0.7 pts
Q1 10:56	Delay of Game on USC, 6 yards · pre-snap	+1% MSU +0.7 pts
Q1 9:22	False Start on USC, 5 yards · pre-snap	+1% MSU +0.9 pts
Q1 6:56	False Start on Michigan State, 5 yards · pre-snap	+1% USC +0.7 pts
Q1 0:32	Holding on USC, 10 yards	0% MSU +0.8 pts
Q2 4:19	Unsportsmanlike Conduct on USC, 23 yards	+1% MSU +1.4 pts
Q3 9:42	Running Into the Kicker on USC, 5 yards	0% MSU +0.9 pts
Q3 9:36	Illegal Substitution on USC, 5 yards · pre-snap	0% MSU +3.1 pts
Q3 9:28	Pass Interference on USC, 15 yards	0% MSU +2.3 pts
Q3 6:02	Illegal Use of Hands on USC, 5 yards	0% MSU +1.7 pts
Q3 4:32	Offside on USC, 5 yards · pre-snap	0% MSU +0.5 pts
Q4 8:25	Face Mask on Michigan State, 5 yards	0% USC +2.2 pts
Q4 2:39	Roughing the Passer on USC, 0 yards	0% MSU 0.0 pts

When it happened

USC’s chance of winning

Numbers mark the biggest luck moments, listed below.

USC 50% Michigan State Q1Q2Q3Q4 1234568

Our in-game win probability: the score, the value of the possession and the time left, starting from the betting line. Overtime has no clock and is drawn at a fixed width. Shaded above the middle while USC was ahead in it, below while Michigan State was.

#	When	What happened	Win probability for	Next drive
1	Q1 1:10	Michigan State converted 3rd & 33rd & 4th downs · 57% expected	+2% MSU	MSU: Punt
2	Q2 11:50	USC converted 3rd & 53rd & 4th downs · 50% expected	+2% USC	USC: Touchdown
3	Q2 8:05	USC was stopped on 4th & 43rd & 4th downs · 55% expected	+2% MSU	USC: Touchdown
4	Q2 4:26	M. Connington made a 29-yard field goalKicks · 88% expected for him	+2% USC	MSU: Missed field goal
5	Q3 5:50	USC fumbled and Michigan State recoveredFumble bounces · loose balls are close to 50/50	+1% MSU	USC: Touchdown
6	Q4 14:47	USC converted 3rd & 33rd & 4th downs · 63% expected	+1% USC	USC: Touchdown
7	Q4 11:49	USC was stopped on 3rd & 33rd & 4th downs · 63% expected	+2% MSU	USC: Touchdown
8	Q4 11:01	USC converted 4th & 33rd & 4th downs · 62% expected	+2% USC	USC: Touchdown

Adjust the assumptions

Disagree with how much of a fumble bounce or a pass interference call is luck? Change it and the coin-flip replay reruns in your browser.

About these numbers

Play-by-play and expected points from CollegeFootballData.com via cfbfastR; win probability from our own model of the score, the possession and the betting line; kicks valued against each kicker’s own record. College play-by-play has no charting of drops or interception-worthy throws and no injury reports, so those kinds of luck aren’t counted here.

Methodology and validation · All Week 4 2025 games · Michigan State · USC

More from Week 4 2025

Michigan at Nebraska MICH 30–27 · replay 39% for the winner
Iowa at Rutgers IOWA 38–28 · replay 80% for the winner
Washington at Washington State WASH 59–24 · replay 80% for the winner
Maryland at Wisconsin MD 27–10 · replay 80% for the winner
Oregon State at Oregon ORE 41–7 · replay 100% for the winner
Purdue at Notre Dame ND 56–30 · replay 100% for the winner
Illinois at Indiana IU 63–10 · replay 100% for the winner
Fresno State at Hawai'i FRES 23–21 · replay 24% for the winner
Troy at Buffalo TROY 21–17 · replay 30% for the winner
Arkansas at Memphis MEM 32–31 · replay 30% for the winner
Syracuse at Clemson SYR 34–21 · replay 34% for the winner
NC State at Duke DUKE 45–33 · replay 35% for the winner

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