luckadjusted

Week 3 2024 · September 22, 2024

49ers at Rams, Week 3 2024: who deserved to win?

The Rams beat the 49ers 27–24, but the 49ers played well enough to win it: they take 7 of 10 replays with the same day's form. Luck ran their way: kicks alone were worth 24 points of win probability to the Rams.

Before kickoff the 49ers were 67% favorites. The biggest swing (Q4, 0:42 left): Defensive Pass Interference on the 49ers (De'Vondre Campbell), 25 yards, worth 13 points of win probability to the Rams.

Final

San Francisco 49ers 24
Los Angeles Rams 27

September 22, 2024 · SoFi Stadium · Closing line: 49ers −6

Luck index +70 Rams very lucky · −70 49ers

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. 49ers win 7, Rams win 3.

  1. 1 SF 38 LA 14
  2. 2 SF 29 LA 13
  3. 3 SF 30 LA 17
  4. 4 SF 27 LA 17
  5. 5 SF 23 LA 16
  6. 6 SF 27 LA 23
  7. 7 SF 19 LA 17
  8. 8 SF 24 LA 27
  9. 9 SF 23 LA 30
  10. 10 SF 14 LA 29

Three other ways to ask

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

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

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

How 4,000 replays ended

49ers win 70% of them, Rams 30%, counting the 5% still level after regulation as half each. The line is what actually happened: Rams by 3.

Show as a table
Final margin in the replaysShare of replays
49ers by 17+21.2%
49ers by 9–1621.4%
49ers by 1–826.8%
Level after regulation4.8%
Rams by 1–816.0%
Rams by 9–166.7%
Rams by 17+3.1%

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.

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 +8.4 points to the Rams: the final margin was Rams by 3, without the luck 49ers by 5.4. 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 the weather), and what happened.

  • J. Moody, 26 yds made · 98% expected
  • J. Karty, 33 yds made · 95% expected
  • J. Moody, 55 yds missed · 67% expected
  • J. Karty, 37 yds made · 92% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: 49ers 7 for 111 yards, Rams 8 for 75 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

WhenFlagWin probability for
Q1 14:25 Face Mask on the Rams, 15 yards +5% SF +1.8 pts
Q1 8:17 Defensive Holding on the Rams (Tre'Davious White), 5 yards +3% SF +1.3 pts
Q1 8:11 Ineligible Downfield Pass on the 49ers, 5 yards, wiping out the play +3% LA +1.3 pts
Q1 5:35 Illegal Contact on the Rams (Quentin Lake), 5 yards +4% SF +1.4 pts
Q1 5:24 Offensive Holding on the 49ers, 10 yards +3% LA +1.2 pts
Q1 4:37 Defensive Pass Interference on the Rams (Kamren Curl), 14 yards +5% SF +2.4 pts
Q2 14:20 Offensive Holding on the Rams (Hunter Long), 10 yards, wiping out the play +3% SF +1.5 pts
Q2 7:44 Intentional Grounding on the Rams (Matthew Stafford), 11 yards +2% SF +0.9 pts
Q3 7:01 Defensive Pass Interference on the 49ers (Isaac Yiadom), 48 yards +6% LA +3.5 pts
Q3 7:01 False Start on the Rams, 5 yards · pre-snap +2% SF +0.6 pts
Q3 4:01 Defensive Holding on the 49ers (Renardo Green), 3 yards +1% LA +0.8 pts
Q3 3:05 Illegal Block Above the Waist on the 49ers, 10 yards +2% LA +0.9 pts
Q4 11:57 Illegal Block Above the Waist on the Rams (Colby Parkinson), 10 yards +2% SF +0.8 pts
Q4 4:14 Offensive Holding on the 49ers (Kyle Juszczyk), 10 yards +3% LA +1.3 pts
Q4 0:42 Defensive Pass Interference on the 49ers (De'Vondre Campbell), 25 yards +13% LA +2.5 pts

49ers penalties, every game · Rams penalties, every game · All teams, 2024

When it happened

Rams’ chance of winning

As low as 6% and as high as 100%. Numbers mark the biggest luck moments, listed below.

nflfastR’s in-game win probability. It ignores the betting line, so it starts near even. Shaded above the middle while the Rams were ahead in it, below while the 49ers were.
#WhenWhat happenedWin probability forNext drive
1 Q2 0:31 The 49ers fumbled and the Rams recoveredFumble bounces · loose balls are close to 50/50 +8% LA SF: Touchdown
2 Q3 7:07 The 49ers converted 3rd & 53rd & 4th downs · 43% expected +7% SF SF: Touchdown
3 Q4 12:00 J. Moody made 26-yard field goalKicks · 98% expected for him +7% LA SF: Missed field goal
4 Q4 8:03 The Rams were stopped on 3rd & 13rd & 4th downs · 74% expected +6% SF LA: Field goal
5 Q4 7:58 The Rams converted 4th & 13rd & 4th downs · 74% expected +7% LA LA: Field goal
6 Q4 2:48 J. Moody missed 55-yard field goalKicks · 67% expected for him, 9 of 12 from 45+ before +8% LA SF: Punt
7 Q4 0:42 Defensive Pass Interference on the 49ers (De'Vondre Campbell), 25 yardsJudgment calls · 5 flags in 4614 snaps before, position avg 1 per 445 +13% LA LA: Field goal
8 Q4 0:05 J. Karty made 37-yard field goalKicks · 92% expected for him +6% LA –

Missing players

Key players (usually on the field for half the snaps or more) who missed this game or part of it, valued by position and quality. The same players are missing in every replay, so this counts as luck in points only.

  • Puka Nacua (LA WR), out (IR) · 1.7 pts
  • Cooper Kupp (LA WR), out · 1.3 pts
  • Tyler Higbee (LA TE), out (IR) · 0.7 pts
  • John Johnson (LA SS), out (IR) · 0.5 pts
  • Steve Avila (LA G), out (IR) · 0.4 pts
  • George Kittle (SF TE), out · 1.1 pts
  • Christian McCaffrey (SF RB), out (IR) · 0.8 pts
  • Dre Greenlaw (SF LB), out (IR) · 0.4 pts
  • Jon Feliciano (SF C), out (IR) · 0.3 pts
  • Ambry Thomas (SF CB), out (IR) · 0.3 pts

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.

Only coin-flips re-rolled

49ers 82% · Rams 18%

Final margin
Rams by 3
Luck in points
8.4 for the Rams
Luck-adjusted margin
49ers by 5.4
Replay with same day's form
49ers 70% · Rams 30% unchanged: why
How much of each is luck?

0% treats it as skill, 100% as pure luck. The tick is our fit.

What counts

We tested momentum on 19,000 lucky breaks and found none, so it's off by default. Why

Flip a play

Force the other outcome, in this game and in every replay: a made kick becomes a miss, a stop becomes a conversion, a flag goes the other way.

About these numbers

Play-by-play and win probability from nflfastR via nflverse; kicks valued against each kicker’s own record; drops and interception-worthy throws from FTN charting; injuries from snap counts and injury reports.

Methodology and validation · All Week 3 2024 games · 49ers · Rams

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