luckadjusted

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 it was a coin flip: replayed with the way both teams played, the Bears win 5 of 10. Luck ran their way: judgment calls alone were worth 2.5 points to the Bears.

Before kickoff the Raiders were 66% favorites. The biggest swing (Q1, 7:58 left): the Raiders converted 3rd & 9, worth 9 points of win probability to the Raiders.

Final

Chicago Bears 20
Las Vegas Raiders 9

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

Luck index +49 Bears lucky · −49 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 26 LV 7
  2. 2 CHI 24 LV 11
  3. 3 CHI 17 LV 8
  4. 4 CHI 30 LV 26
  5. 5 CHI 9 LV 7
  6. 6 CHI 17 LV 19
  7. 7 CHI 7 LV 12
  8. 8 CHI 13 LV 21
  9. 9 CHI 13 LV 26
  10. 10 CHI 3 LV 23

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 51% of them, Raiders 49%, counting the 6% 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+9.1%
Bears by 9–1615.0%
Bears by 1–823.6%
Level after regulation6.2%
Raiders by 1–822.7%
Raiders by 9–1614.9%
Raiders by 17+8.6%

Where the luck was

Take the luck out

The final margin was Bears by 11. Remove the luck, one kind at a time, and it becomes Bears by 4.7.

Each row takes one kind of luck out of the margin. Color shows which team it helped. Luck shares are the fitted ones (how much of each component 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.

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 · 29% expected +9% LV LV: Field goal
2 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
3 Q2 11:02 The Raiders were stopped on 3rd & 13rd & 4th downs · 74% expected +5% CHI LV: Turnover on downs
4 Q2 7:26 The Bears converted 3rd & 13rd & 4th downs · 72% expected +5% CHI CHI: Touchdown
5 Q2 3:56 The Bears converted 3rd & 73rd & 4th downs · 32% expected +6% CHI CHI: Touchdown
6 Q4 12:49 The Raiders converted 4th & 13rd & 4th downs · 73% expected +5% LV LV: Touchdown
7 Q4 7:26 The Bears converted 3rd & 123rd & 4th downs · 23% expected +9% CHI CHI: Field goal
8 Q4 2:50 C. Santos made 46-yard field goalKicks · 80% expected for him, 9 of 14 from 45+ before +8% 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 77% · Raiders 23%

Final margin
Bears by 11
Luck in points
6.3 for the Bears
Luck-adjusted margin
Bears by 4.7
Replay with same day's form
Bears 51% · Raiders 49% 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 (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

More from Week 5 2021