Week 15 2021 · December 19, 2021
No FTN charting for this game (drops and interception-worthy throws are not modelled).
Panthers at Bills, Week 15 2021: who deserved to win?
The Bills beat the Panthers 31–14, and it was no fluke: replayed with the way both teams actually played, the Bills win 8 of 10.
Before kickoff the Bills were 85% favorites. The biggest swing (Q1, 4:29 left): the Panthers converted 3rd & 9, worth 13 points of win probability to the Panthers.
Final
 Carolina Panthers | 14 |
|---|---|
 Buffalo Bills | 31 |
Replay with same day's form
Luck index +17 Bills about even · −17 Panthers
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. Panthers win 2, Bills win 8.
- 1 CAR 20 BUF 8
- 2 CAR 14 BUF 10
- 3 CAR 10 BUF 12
- 4 CAR 12 BUF 16
- 5 CAR 17 BUF 24
- 6 CAR 10 BUF 20
- 7 CAR 16 BUF 30
- 8 CAR 20 BUF 37
- 9 CAR 0 BUF 22
- 10 CAR 7 BUF 37
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
Panthers win 17% of them, Bills 83%, counting the 1% still level after regulation as half each. The line is what actually happened: Bills by 17.
Show as a table
| Final margin in the replays | Share of replays |
|---|---|
| Panthers by 17+ | 1.3% |
| Panthers by 9–16 | 4.9% |
| Panthers by 1–8 | 10.3% |
| Level after regulation | 1.1% |
| Bills by 1–8 | 25.3% |
| Bills by 9–16 | 21.3% |
| Bills by 17+ | 35.7% |
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.
Penalties: Panthers 5 for 55 yards, Bills 8 for 67 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 13:14 | Ineligible Downfield Pass on the Bills, 5 yards, wiping out the play | +3% CAR +1.4 pts |
| Q1 8:29 | Offensive Holding on the Bills, 10 yards | +1% CAR +1.0 pts |
| Q2 10:57 | Face Mask on the Panthers, 15 yards | +3% BUF +1.8 pts |
| Q2 9:36 | Defensive Offside on the Bills (Ed Oliver), 5 yards · pre-snap | 0% CAR +0.3 pts |
| Q2 3:51 | Neutral Zone Infraction on the Panthers (Stephon Gilmore), 5 yards · pre-snap | +1% BUF +0.4 pts |
| Q2 1:40 | Offensive Holding on the Bills, 10 yards | +2% CAR +0.5 pts |
| Q2 0:41 | Defensive Too Many Men on Field on the Panthers, 5 yards · pre-snap | +2% BUF +0.3 pts |
| Q2 0:31 | False Start on the Bills, 5 yards · pre-snap | +2% CAR +0.3 pts |
| Q2 0:26 | Roughing the Passer on the Panthers (Brian Burns), 15 yards | +4% BUF +1.5 pts |
| Q3 7:56 | Unnecessary Roughness on the Panthers (Bravvion Roy), 15 yards | +2% BUF +1.9 pts |
| Q3 5:09 | Defensive Pass Interference on the Bills, 6 yards | +2% CAR +1.3 pts |
| Q4 14:55 | Taunting on the Bills, 11 yards | +1% CAR +1.0 pts |
| Q4 1:55 | Unnecessary Roughness on the Bills, 15 yards | 0% CAR +0.9 pts |
Panthers penalties, every game · Bills penalties, every game · All teams, 2021
When it happened
Bills’ chance of winning
As low as 45% and as high as 100%. Numbers mark the biggest luck moments, listed below.
| # | When | What happened | Win probability for | Next drive |
|---|---|---|---|---|
| 1 | Q1 8:32 | The Panthers were stopped on 4th & 93rd & 4th downs · 26% expected | +8% BUF | CAR: Turnover on downs |
| 2 | Q1 5:54 | The Panthers fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 | +6% CAR | CAR: Turnover on downs |
| 3 | Q1 4:29 | The Panthers converted 3rd & 93rd & 4th downs · 26% expectedThe Panthers fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 | +13% CAR | CAR: Turnover on downs |
| 4 | Q1 2:05 | The Panthers were stopped on 4th & 13rd & 4th downs · 70% expected | +6% BUF | CAR: Punt |
| 5 | Q1 1:10 | The Bills converted 3rd & 23rd & 4th downs · 61% expected | +7% BUF | BUF: Touchdown |
| 6 | Q2 1:48 | The Panthers’ two-point try was good3rd & 4th downs · 47% expected | +4% CAR | CAR: Punt |
| 7 | Q3 14:10 | The Bills converted 3rd & 83rd & 4th downs · 33% expected | +4% BUF | BUF: Punt |
| 8 | Q4 11:07 | The Panthers converted 3rd & 63rd & 4th downs · 34% expected | +5% CAR | CAR: 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.
- Dion Dawkins (BUF T), out (IR) · 1.3 pts
- Tre'Davious White (BUF CB), out (IR) · 1.2 pts
- Emmanuel Sanders (BUF WR), out · 0.8 pts
- Jon Feliciano (BUF G), out · 0.3 pts
- Donte Jackson (CAR CB), out (IR) · 0.8 pts
- Trenton Scott (CAR T), out · 0.6 pts
- Matt Paradis (CAR C), out (IR) · 0.5 pts
- Christian McCaffrey (CAR RB), out (IR) · 0.4 pts
- Derrick Brown (CAR DT), out (IR) · 0.4 pts
- A.J. Bouye (CAR CB), out · 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
Panthers 0% · Bills 100%
- Final margin
- Bills by 17
- Luck in points
- 1.2 for the Panthers
- Luck-adjusted margin
- Bills by 18.2
- Replay with same day's form
- Panthers 17% · Bills 83% 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 15 2021 games · 
Panthers · 
Bills
More from Week 15 2021
- Chiefs at Chargers KC 34–28 · replay 73% for the winner
- Patriots at Colts IND 27–17 · replay 75% for the winner
- Cardinals at Lions DET 30–12 · replay 20% for the winner
- Cowboys at Giants DAL 21–6 · replay 73% for the winner
- Texans at Jaguars HOU 30–16 · replay 31% for the winner
- Jets at Dolphins MIA 31–24 · replay 72% for the winner
- Titans at Steelers PIT 19–13 · replay 67% for the winner
- Falcons at 49ers SF 31–13 · replay 89% for the winner
- Bengals at Broncos CIN 15–10 · replay 67% for the winner
- Packers at Ravens GB 31–30 · replay 77% for the winner
- Saints at Buccaneers NO 9–0 · replay 17% for the winner
- Raiders at Browns LV 16–14 · replay 52% for the winner
- Vikings at Bears MIN 17–9 · replay 44% for the winner
- Seahawks at Rams LA 20–10 · replay 89% for the winner
- Washington at Eagles PHI 27–17 · replay 92% for the winner