Week 9 2021 · November 8, 2021
No FTN charting for this game (drops and interception-worthy throws are not modelled).
Bears at Steelers, Week 9 2021: who deserved to win?
The Steelers beat the Bears 29–27, but the Bears played well enough to win it: they take 7 of 10 replays with the same day's form. Luck ran their way: judgment calls alone were worth 10.0 points to the Steelers.
The Steelers won on an off day: their defense played far below its usual level. In a fresh game against the Bears they would win 67% of the time; with this day’s form, 34%. The numbers
Before kickoff the Steelers were 70% favorites. The biggest swing (Q4, 0:02 left): C. Santos missed 65-yard field goal, worth 55 points of win probability to the Steelers.
Final
 Chicago Bears | 27 |
|---|---|
 Pittsburgh Steelers | 29 |
Replay with same day's form
Luck index +66 Steelers very lucky · −66 Bears
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. Bears win 7, Steelers win 3.
- 1 CHI 34 PIT 6
- 2 CHI 44 PIT 24
- 3 CHI 36 PIT 21
- 4 CHI 31 PIT 20
- 5 CHI 38 PIT 30
- 6 CHI 38 PIT 33
- 7 CHI 29 PIT 27
- 8 CHI 30 PIT 32
- 9 CHI 23 PIT 30
- 10 CHI 23 PIT 40
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.
The Steelers won on an off day
Their defense played far below its usual level. In a fresh game against the Bears they would win 67% of the time; with this day’s form, 34%.
Same teams, fresh game
Replay with same day's form
33 points apart for the Steelers: the gap is how differently this game went from what the two teams usually are.
| Unit | This game | Usual level | Better or worse than usual |
|---|---|---|---|
| Bears offenseEPA per play gained | +0.21 | +0.07 | better by 0.14 |
| Bears defenseEPA per play allowed | +0.04 | +0.13 | better by 0.09 |
| Steelers offenseEPA per play gained | +0.04 | +0.09 | worse by 0.05 |
| Steelers defenseEPA per play allowed | +0.21 | +0.08 | worse by 0.13 |
EPA (expected points added) per play on competitive snaps, turnovers left out because they are valued as luck. Usual level: the team’s earlier games this season plus half of last season, pulled toward the league average. One team’s defense and the other team’s offense are the same snaps, so one game can’t fully say whose day it was; it shows how far this one was from both teams’ norms.
How 4,000 replays ended
Bears win 66% of them, Steelers 34%, counting the 3% still level after regulation as half each. The line is what actually happened: Steelers by 2.
Show as a table
| Final margin in the replays | Share of replays |
|---|---|
| Bears by 17+ | 20.4% |
| Bears by 9–16 | 19.6% |
| Bears by 1–8 | 24.3% |
| Level after regulation | 2.5% |
| Steelers by 1–8 | 17.7% |
| Steelers by 9–16 | 10.4% |
| Steelers by 17+ | 5.1% |
Where the luck was
Take the luck out
The final margin was Steelers by 2. Remove the luck, one kind at a time, and it becomes Bears by 14.2.
The kicks
How likely each kicker was to make that kick (his own record, the distance and the weather), and what happened.
- C. Santos, 30 yds made · 96% expected
- C. Santos, 22 yds made · 99% expected
- C. Boswell, 54 yds made · 68% expected
- C. Boswell, 52 yds made · 72% expected
- C. Boswell, 40 yds made · 88% expected
- C. Santos, 65 yds missed · 49% expected
- Extra point missed · 93% expected
When it happened
Steelers’ chance of winning
Numbers mark the biggest luck moments, listed below.
| # | When | What happened | Win probability for | Next drive |
|---|---|---|---|---|
| 1 | Q1 11:41 | The Steelers converted 3rd & 73rd & 4th downs · 33% expected | +10% PIT | PIT: Touchdown |
| 2 | Q3 9:19 | Low Block on the Bears, 15 yards, wiping out the playJudgment calls | +8% PIT | PIT: Touchdown |
| 3 | Q4 6:47 | The Steelers fumbled and the Bears recoveredFumble bounces · loose balls are close to 50/50Return touchdown by the BearsSpecial teams | +28% CHI | PIT: Field goal |
| 4 | Q4 3:40 | Taunting on the Bears (Cassius Marsh), 15 yardsJudgment calls · 3 flags in 957 snaps before, position avg 1 per 409 | +8% PIT | PIT: Field goal |
| 5 | Q4 2:00 | The Bears converted 3rd & 23rd & 4th downs · 59% expected | +22% CHI | CHI: Touchdown |
| 6 | Q4 0:30 | C. Boswell made 40-yard field goalKicks · 88% expected for him | +10% PIT | – |
| 7 | Q4 0:22 | Illegal Contact on the Steelers, 5 yards, wiping out the playJudgment calls | +15% PIT | CHI: Missed field goal |
| 8 | Q4 0:02 | C. Santos missed 65-yard field goalKicks · 49% expected for him, 11 of 16 from 45+ before | +55% PIT | – |
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.
- JuJu Smith-Schuster (PIT WR), out (IR) · 0.9 pts
- Tyson Alualu (PIT DE), out (IR) · 0.4 pts
- Germain Ifedi (CHI T), out (IR) · 0.8 pts
- Eddie Jackson (CHI SS), out · 0.8 pts
- Khalil Mack (CHI LB), out · 0.6 pts
- Alec Ogletree (CHI LB), out · 0.4 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
Bears 97% · Steelers 3%
- Final margin
- Steelers by 2
- Luck in points
- 16.2 for the Steelers
- Luck-adjusted margin
- Bears by 14.2
- Replay with same day's form
- Bears 66% · Steelers 34% 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 9 2021 games · 
Bears · 
Steelers
More from Week 9 2021
- Jets at Colts IND 45–30 · replay 82% for the winner
- Falcons at Saints ATL 27–25 · replay 58% for the winner
- Bills at Jaguars JAX 9–6 · replay 41% for the winner
- Browns at Bengals CLE 41–16 · replay 63% for the winner
- Broncos at Cowboys DEN 30–16 · replay 52% for the winner
- Texans at Dolphins MIA 17–9 · replay 58% for the winner
- Raiders at Giants NYG 23–16 · replay 13% for the winner
- Vikings at Ravens BAL 34–31 · replay 92% for the winner
- Patriots at Panthers NE 24–6 · replay 82% for the winner
- Chargers at Eagles LAC 27–24 · replay 79% for the winner
- Cardinals at 49ers ARI 31–17 · replay 84% for the winner
- Packers at Chiefs KC 13–7 · replay 68% for the winner
- Titans at Rams TEN 28–16 · replay 35% for the winner