luckadjusted
NFL Week 9 · 2026

Week 5 2021 · October 10, 2021

No FTN charting for this game (drops and interception-worthy throws are not modelled).

Bears at Raiders, Week 5 2021: who deserved to win?

The Bears beat the Raiders 20–9, but the replays call it close to a coin flip: with the way both teams played, the Bears win 5 of 10.

Before kickoff the Raiders were 66% favorites. The biggest swing (Q4, 7:26 left): the Bears converted 3rd & 12, worth 9 points of win probability to the Bears.

Final

Chicago Bears 20
Las Vegas Raiders 9

October 10, 2021 · Allegiant Stadium · Closing line: Raiders −5.5

Luck index +51 Bears lucky · −51 Raiders

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 5, Raiders win 5.

  1. 1 CHI 29 LV 9
  2. 2 CHI 16 LV 3
  3. 3 CHI 28 LV 20
  4. 4 CHI 20 LV 14
  5. 5 CHI 12 LV 10
  6. 6 CHI 14 LV 15
  7. 7 CHI 13 LV 17
  8. 8 CHI 14 LV 22
  9. 9 CHI 10 LV 22
  10. 10 CHI 13 LV 31

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

Bears win 49% of them, Raiders 51%, counting the 7% still level after regulation as half each. The line is what actually happened: Bears by 11.

Show as a table
Final margin in the replaysShare of replays
Bears by 17+8.6%
Bears by 9–1614.7%
Bears by 1–823.1%
Level after regulation6.7%
Raiders by 1–824.5%
Raiders by 9–1614.5%
Raiders by 17+7.9%

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.

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 +4.8 points to the Bears: the final margin was Bears by 11, without the luck Bears by 6.2. 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.

  • D. Carlson, 31 yds made · 96% expected
  • C. Santos, 46 yds made · 80% expected
  • C. Santos, 46 yds made · 80% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Bears 8 for 70 yards, Raiders 10 for 82 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

WhenFlagWin probability for
Q1 14:11 False Start on the Bears, 5 yards · pre-snap +2% LV +0.7 pts
Q1 10:52 Neutral Zone Infraction on the Raiders (Yannick Ngakoue), 5 yards · pre-snap +2% CHI +0.8 pts
Q1 9:07 Offensive Holding on the Raiders, 10 yards, wiping out the play +4% CHI +1.9 pts
Q1 4:22 Offensive Holding on the Raiders (Foster Moreau), 10 yards, wiping out the play +5% CHI +2.4 pts
Q1 3:25 Delay of Game on the Bears, 5 yards · pre-snap +1% LV +0.5 pts
Q1 3:09 Roughing the Passer on the Raiders (Yannick Ngakoue), 15 yards +4% CHI +1.8 pts
Q2 15:00 Roughing the Passer on the Raiders (Maxx Crosby), 5 yards +1% CHI +0.5 pts
Q2 14:16 Illegal Use of Hands on the Raiders (Johnathan Abram), 3 yards +2% CHI +0.6 pts
Q2 12:12 Defensive Pass Interference on the Bears (Roquan Smith), 17 yards +6% LV +0.9 pts
Q2 10:18 Unnecessary Roughness on the Bears (Mario Edwards), 13 yards +3% LV +1.2 pts
Q3 9:19 False Start on the Raiders, 5 yards · pre-snap +2% CHI +0.5 pts
Q3 0:04 Neutral Zone Infraction on the Bears (Eddie Jackson), 4 yards · pre-snap +2% LV +0.9 pts
Q4 11:45 Unnecessary Roughness on the Bears (Mario Edwards), 14 yards +5% LV +1.7 pts
Q4 9:10 Unnecessary Roughness on the Bears (Roquan Smith), 2 yards +3% LV +0.7 pts
Q4 8:58 Defensive Pass Interference on the Raiders (Amik Robertson), 14 yards +2% CHI +0.9 pts
Q4 8:15 Offensive Pass Interference on the Bears (Allen Robinson), 10 yards +5% LV +1.3 pts
Q4 2:10 False Start on the Raiders, 5 yards · pre-snap 0% CHI +0.3 pts
Q4 0:13 Offensive Holding on the Raiders, 10 yards 0% CHI +0.2 pts

Bears penalties, every game · Raiders penalties, every game · All teams, 2021

When it happened

Raiders’ chance of winning

As low as 0% and as high as 73%. 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 Raiders were ahead in it, below while the Bears were.
#WhenWhat happenedWin probability forNext drive
1 Q1 7:58 The Raiders converted 3rd & 93rd & 4th downs · 30% expected +8% LV LV: Field goal
2 Q1 4:22 Offensive Holding on the Raiders (Foster Moreau), 10 yards, wiping out the playJudgment calls · 3 flags in 1287 snaps before, position avg 1 per 269 +5% CHI CHI: Touchdown
3 Q2 12:12 Defensive Pass Interference on the Bears (Roquan Smith), 17 yardsJudgment calls · 4 flags in 2045 snaps before, position avg 1 per 409 +6% LV LV: Turnover on downs
4 Q2 11:02 The Raiders were stopped on 3rd & 13rd & 4th downs · 75% expected +5% CHI LV: Turnover on downs
5 Q2 3:56 The Bears converted 3rd & 73rd & 4th downs · 34% expected +6% CHI CHI: Touchdown
6 Q4 11:45 Unnecessary Roughness on the Bears (Mario Edwards), 14 yardsJudgment calls · 2 flags in 777 snaps before, position avg 1 per 273 +5% LV LV: Touchdown
7 Q4 7:26 The Bears converted 3rd & 123rd & 4th downs · 24% expected +9% CHI CHI: Field goal
8 Q4 2:50 C. Santos made a 46-yard field goalKicks · 80% expected for him, 9 of 14 from 45+ before +7% CHI CHI: Field goal

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.

  • Trayvon Mullen (LV CB), out (IR) · 0.5 pts
  • Denzelle Good (LV G/T), out (IR) · 0.2 pts
  • David Montgomery (CHI RB), out (IR) · 0.5 pts
  • Akiem Hicks (CHI DT), out · 0.5 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 93% · Raiders 7%

Final margin
Bears by 11
Luck in points
4.8 for the Bears
Luck-adjusted margin
Bears by 6.2
Replay with same day's form
Bears 49% · Raiders 51% unchanged: why
How much of each is luck?

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

What counts

None by default: our tests measured no carryover after a lucky break. Slide it up to count a break for more than its own swing. 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 (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 5 2021 games · Bears · Raiders

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