Week 10 2021 · November 15, 2021
No FTN charting for this game (drops and interception-worthy throws are not modelled).
Rams at 49ers, Week 10 2021: who deserved to win?
The 49ers beat the Rams 31–10, but the replays call it close to a coin flip: with the way both teams played, the 49ers win 5 of 10.
Before kickoff the Rams were 60% favorites. The biggest swing (Q1, 0:58 left): Return touchdown by the 49ers, worth 9 points of win probability to the 49ers.
Final
 Los Angeles Rams | 10 |
|---|---|
 San Francisco 49ers | 31 |
Replay with same day's form
Luck index +51 49ers lucky · −51 Rams
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. Rams win 5, 49ers win 5.
- 1 LA 28 SF 7
- 2 LA 36 SF 23
- 3 LA 23 SF 14
- 4 LA 37 SF 31
- 5 LA 13 SF 10
- 6 LA 10 SF 12
- 7 LA 20 SF 25
- 8 LA 15 SF 24
- 9 LA 14 SF 27
- 10 LA 13 SF 35
Your call
Did the 49ers earn it, or get lucky?
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, drop, conversion and judgment call redrawn; everything else fixed. The narrowest view of luck.
How 4,000 replays ended
Rams win 51% of them, 49ers 49%, counting the 7% still level after regulation as half each. The line is what actually happened: 49ers by 21.
Show as a table
| Final margin in the replays | Share of replays |
|---|---|
| Rams by 17+ | 9.7% |
| Rams by 9–16 | 14.3% |
| Rams by 1–8 | 23.1% |
| Level after regulation | 6.6% |
| 49ers by 1–8 | 23.3% |
| 49ers by 9–16 | 13.8% |
| 49ers by 17+ | 9.2% |
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.
The kicks
How likely each kicker was to make that kick (his own record, the distance and the weather), and what happened.
- R. Gould, 50 yds made · 69% expected
- M. Gay, 37 yds made · 92% expected
Penalties: Rams 5 for 35 yards, 49ers 9 for 53 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 half toward luck; pre-snap fouls, which repeat, don’t count. How calls are valued
| When | Flag | Win probability for |
|---|---|---|
| Q1 7:51 | Defensive Offside on the Rams (Terrell Lewis), 5 yards · pre-snap | +3% SF +0.5 pts |
| Q1 1:54 | Unnecessary Roughness on the Rams, 15 yards | +3% SF +1.4 pts |
| Q2 13:16 | Offensive Holding on the 49ers (Ross Dwelley), 9 yards | +1% LA +0.7 pts |
| Q2 11:52 | Defensive Offside on the Rams (Leonard Floyd), 5 yards · pre-snap | +1% SF +1.0 pts |
| Q2 8:41 | False Start on the 49ers, 5 yards · pre-snap | +2% LA +0.8 pts |
| Q2 1:35 | False Start on the Rams, 5 yards · pre-snap | +1% SF +0.7 pts |
| Q3 10:52 | False Start on the 49ers (George Kittle), 5 yards · pre-snap | +1% LA +0.5 pts |
| Q3 5:48 | Illegal Shift on the 49ers (Jauan Jennings), 5 yards · pre-snap | 0% SF +0.5 pts |
| Q4 12:49 | False Start on the 49ers (Jeff Wilson), 5 yards · pre-snap | 0% LA +0.6 pts |
| Q4 10:35 | Defensive Pass Interference on the 49ers, 6 yards | 0% LA +0.9 pts |
| Q4 9:04 | Defensive Pass Interference on the 49ers, 5 yards, wiping out the play | 0% LA +3.9 pts |
| Q4 6:53 | Encroachment on the 49ers (Arik Armstead), 5 yards · pre-snap | 0% LA +0.6 pts |
| Q4 6:15 | Illegal Forward Pass on the Rams (Matthew Stafford), 5 yards | 0% SF +0.5 pts |
| Q4 4:15 | Roughing the Passer on the 49ers (Kentavius Street), 8 yards | 0% LA +1.1 pts |
Rams penalties, every game · 49ers penalties, every game · All teams, 2021
When it happened
49ers’ chance of winning
Numbers mark the biggest luck moments, listed below.
| # | When | What happened | Win probability for | Next drive |
|---|---|---|---|---|
| 1 | Q1 10:26 | The 49ers converted 3rd & 63rd & 4th downs · 36% expected | +5% SF | SF: Touchdown |
| 2 | Q1 7:51 | Defensive Offside on the Rams (Terrell Lewis), 5 yardsPre-snap flags · 3 flags in 459 snaps before, position avg 1 per 409 | +3% SF | SF: Touchdown |
| 3 | Q1 7:02 | The 49ers converted 3rd & 13rd & 4th downs · 73% expected | +3% SF | SF: Touchdown |
| 4 | Q1 5:07 | The 49ers converted 3rd & 43rd & 4th downs · 45% expected | +5% SF | SF: Touchdown |
| 5 | Q1 1:59 | The 49ers converted 3rd & 63rd & 4th downs · 29% expected | +5% SF | SF: Touchdown |
| 6 | Q1 0:58 | Return touchdown by the 49ersSpecial teams | +9% SF | SF: Opp touchdown |
| 7 | Q2 13:20 | The Rams converted 3rd & 93rd & 4th downs · 23% expected | +4% LA | LA: Touchdown |
| 8 | Q2 8:23 | The 49ers converted 3rd & 73rd & 4th downs · 34% expected | +4% SF | SF: Touchdown |
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.
- Mike McGlinchey (SF T), out (IR) · 0.9 pts
- Jaquiski Tartt (SF SS), out (IR) · 0.4 pts
- Javon Kinlaw (SF DT), out (IR) · 0.3 pts
- Robert Woods (LA WR), out · 1.0 pts
- Donte Deayon (LA CB), out · 0.6 pts
- Justin Hollins (LA LB), out (IR) · 0.1 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
Rams 0% · 49ers 100%
- Final margin
- 49ers by 21
- Luck in points
- 2.2 for the 49ers
- Luck-adjusted margin
- 49ers by 18.8
- Replay with same day's form
- Rams 51% · 49ers 49% unchanged: why
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 (not available for this game); injuries from snap counts and injury reports. No FTN charting for this game (drops and interception-worthy throws are not modelled).
Methodology and validation · All Week 10 2021 games · 
Rams · 
49ers
More from Week 10 2021
- Ravens at Dolphins MIA 22–10 · replay 35% for the winner
- Falcons at Cowboys DAL 43–3 · replay 94% for the winner
- Bills at Jets BUF 45–17 · replay 96% for the winner
- Browns at Patriots NE 45–7 · replay 96% for the winner
- Lions at Steelers PIT 16–16 · replay 35% for the winner
- Jaguars at Colts IND 23–17 · replay 67% for the winner
- Saints at Titans TEN 23–21 · replay 36% for the winner
- Buccaneers at Washington WAS 29–19 · replay 18% for the winner
- Panthers at Cardinals CAR 34–10 · replay 53% for the winner
- Vikings at Chargers MIN 27–20 · replay 23% for the winner
- Eagles at Broncos PHI 30–13 · replay 71% for the winner
- Seahawks at Packers GB 17–0 · replay 80% for the winner
- Chiefs at Raiders KC 41–14 · replay 84% for the winner