luckadjusted
NFL Week 9 · 2026

Week 4 2020 · October 4, 2020

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

Colts at Bears, Week 4 2020: who deserved to win?

The Colts beat the Bears 19–11, and the replays lean their way: with the same day's form, they win 6 of 10.

Before kickoff the Colts were 60% favorites. The biggest swing (Q1, 10:11 left): the Colts converted 3rd & 9, worth 9 points of win probability to the Colts.

Final

Indianapolis Colts 19
Chicago Bears 11

October 4, 2020 · Soldier Field · Closing line: Colts −3.5

Luck index +40 Colts lucky · −40 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. Colts win 6, Bears win 4.

  1. 1 IND 40 CHI 17
  2. 2 IND 38 CHI 23
  3. 3 IND 33 CHI 22
  4. 4 IND 18 CHI 10
  5. 5 IND 30 CHI 26
  6. 6 IND 17 CHI 16
  7. 7 IND 23 CHI 26
  8. 8 IND 13 CHI 20
  9. 9 IND 10 CHI 23
  10. 10 IND 13 CHI 33

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

Colts win 60% of them, Bears 40%, counting the 3% still level after regulation as half each. The line is what actually happened: Colts by 8.

Show as a table
Final margin in the replaysShare of replays
Colts by 17+14.0%
Colts by 9–1617.5%
Colts by 1–827.3%
Level after regulation2.9%
Bears by 1–821.2%
Bears by 9–1611.8%
Bears by 17+5.3%

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 +4.2 points to the Colts: the final margin was Colts by 8, without the luck Colts by 3.8. 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.

  • C. Santos, 27 yds made · 96% expected
  • R. Blankenship, 21 yds made · 98% expected
  • R. Blankenship, 30 yds made · 95% expected
  • R. Blankenship, 44 yds made · 80% expected
  • R. Blankenship, 30 yds made · 95% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Colts 8 for 76 yards, Bears 8 for 103 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 12:17 Neutral Zone Infraction on the Colts, 5 yards · pre-snap +4% CHI +0.7 pts
Q1 11:43 Offensive Holding on the Colts, 10 yards +1% CHI +0.8 pts
Q1 11:24 Defensive Pass Interference on the Bears (Kyle Fuller), 8 yards +1% IND +0.6 pts
Q1 11:19 Offensive Holding on the Colts (Jack Doyle), 10 yards, wiping out the play +5% CHI +1.7 pts
Q1 4:54 Defensive Holding on the Colts (Khari Willis), 5 yards +1% CHI +0.4 pts
Q2 14:34 Delay of Game on the Colts, 4 yards · pre-snap +1% CHI +0.8 pts
Q2 14:29 Offensive Holding on the Bears (Kindle Vildor), 7 yards +1% IND +0.6 pts
Q2 7:49 Horse Collar Tackle on the Bears (Robert Quinn), 15 yards +6% IND +1.6 pts
Q2 2:16 Unsportsmanlike Conduct on the Bears (Cordarrelle Patterson), 15 yards +3% IND +1.0 pts
Q2 1:58 False Start on the Colts, 5 yards · pre-snap +1% CHI +0.3 pts
Q2 1:12 Defensive Pass Interference on the Bears (Kyle Fuller), 28 yards +4% IND +2.0 pts
Q3 10:16 Offensive Holding on the Bears (Buster Skrine), 5 yards +1% IND +0.5 pts
Q4 12:32 Defensive Pass Interference on the Colts (Khari Willis), 32 yards +6% CHI +4.2 pts
Q4 12:21 Neutral Zone Infraction on the Colts (Ben Banogu), 5 yards · pre-snap +1% CHI +0.6 pts
Q4 10:59 Face Mask on the Bears (Akiem Hicks), 15 yards +1% IND +1.5 pts
Q4 3:47 Illegal Block Above the Waist on the Bears (Barkevious Mingo), 10 yards 0% IND +0.8 pts

Colts penalties, every game · Bears penalties, every game · All teams, 2020

When it happened

Bears’ chance of winning

As low as 0% and as high as 55%. 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 Bears were ahead in it, below while the Colts were.
#WhenWhat happenedWin probability forNext drive
1 Q1 11:19 Offensive Holding on the Colts (Jack Doyle), 10 yards, wiping out the playJudgment calls · 5 flags in 887 snaps before, position avg 1 per 276 +5% CHI CHI: Punt
2 Q1 10:11 The Colts converted 3rd & 93rd & 4th downs · 28% expected +9% IND IND: Touchdown
3 Q1 8:15 The Colts converted 3rd & 53rd & 4th downs · 40% expected +6% IND IND: Touchdown
4 Q2 9:32 The Bears were stopped on 3rd & 53rd & 4th downs · 34% expected +5% IND CHI: Field goal
5 Q2 8:45 The Colts converted 3rd & 73rd & 4th downs · 33% expected +5% IND IND: Field goal
6 Q2 7:49 Horse Collar Tackle on the Bears (Robert Quinn), 15 yardsJudgment calls · 3 flags in 765 snaps before, position avg 1 per 395 +6% IND IND: Field goal
7 Q2 5:20 The Colts converted 3rd & 103rd & 4th downs · 27% expected +5% IND IND: Field goal
8 Q4 12:32 Defensive Pass Interference on the Colts (Khari Willis), 32 yardsJudgment calls · 1 flag in 848 snaps before, position avg 1 per 510 +6% CHI CHI: Turnover

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.

  • T.J. Carrie (IND CB), out · 0.4 pts
  • Malik Hooker (IND FS), out (IR) · 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

Colts 77% · Bears 23%

Final margin
Colts by 8
Luck in points
4.2 for the Colts
Luck-adjusted margin
Colts by 3.8
Replay with same day's form
Colts 60% · Bears 40% 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 4 2020 games · Colts · Bears

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