luckadjusted
NFL Week 9 · 2026

Week 15 2020 · December 20, 2020

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

Bears at Vikings, Week 15 2020: who deserved to win?

The Bears beat the Vikings 33–27, but the replays lean toward the Vikings: they take 6 of 10 with the same day's form. Luck ran their way: 3rd & 4th downs alone were worth 11 points of win probability to the Bears.

Before kickoff the Vikings were 57% favorites. The biggest swing (Q4, 2:00 left): the Vikings were stopped on 4th & 1, worth 20 points of win probability to the Bears.

Final

Chicago Bears 33
Minnesota Vikings 27

December 20, 2020 · U.S. Bank Stadium · Closing line: Vikings −2.5

Luck index +61 Bears very lucky · −61 Vikings

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 4, Vikings win 6.

  1. 1 CHI 35 MIN 16
  2. 2 CHI 48 MIN 37
  3. 3 CHI 20 MIN 14
  4. 4 CHI 24 MIN 22
  5. 5 CHI 26 MIN 27
  6. 6 CHI 13 MIN 17
  7. 7 CHI 33 MIN 41
  8. 8 CHI 37 MIN 48
  9. 9 CHI 21 MIN 38
  10. 10 CHI 6 MIN 30

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 39% of them, Vikings 61%, counting the 3% still level after regulation as half each. The line is what actually happened: Bears by 6.

Show as a table
Final margin in the replaysShare of replays
Bears by 17+6.6%
Bears by 9–1612.0%
Bears by 1–820.7%
Level after regulation2.5%
Vikings by 1–826.9%
Vikings by 9–1616.4%
Vikings by 17+14.9%

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 +1.6 points to the Bears: the final margin was Bears by 6, without the luck Bears by 4.4. 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, 42 yds made · 87% expected
  • C. Santos, 35 yds made · 93% expected
  • D. Bailey, 24 yds made · 98% expected
  • D. Bailey, 22 yds made · 98% expected
  • C. Santos, 48 yds made · 75% expected
  • C. Santos, 42 yds made · 87% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Bears 4 for 36 yards, Vikings 1 for 5 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
Q2 9:32 Neutral Zone Infraction on the Vikings (D.J. Wonnum), 5 yards · pre-snap +4% CHI +0.9 pts
Q2 8:21 Delay of Game on the Bears, 5 yards · pre-snap +2% MIN +0.8 pts
Q2 1:02 Illegal Contact on the Bears (Danny Trevathan), 5 yards 0% CHI +0.3 pts
Q3 12:51 Roughing the Passer on the Bears (Akiem Hicks), 14 yards +5% MIN +1.3 pts
Q4 10:52 Defensive Pass Interference on the Bears (Kindle Vildor), 12 yards +4% MIN +1.8 pts

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

When it happened

Vikings’ chance of winning

As low as 0% and as high as 62%. 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 Vikings were ahead in it, below while the Bears were.
#WhenWhat happenedWin probability forNext drive
1 Q1 9:22 The Bears converted 3rd & 33rd & 4th downs · 52% expected +6% CHI CHI: Touchdown
2 Q1 4:49 The Vikings converted 3rd & 33rd & 4th downs · 47% expected +7% MIN MIN: Touchdown
3 Q2 5:52 The Vikings were stopped on 4th & 13rd & 4th downs · 77% expected +7% CHI MIN: Field goal
4 Q3 9:37 The Bears converted 3rd & 43rd & 4th downs · 46% expected +6% CHI CHI: Touchdown
5 Q3 7:27 The Bears converted 3rd & 113rd & 4th downs · 25% expected +9% CHI CHI: Touchdown
6 Q4 8:57 The Vikings converted 3rd & 53rd & 4th downs · 44% expected +6% MIN MIN: Touchdown
7 Q4 2:09 The Vikings were stopped on 3rd & 13rd & 4th downs · 76% expected +8% CHI MIN: Turnover on downs
8 Q4 2:00 The Vikings were stopped on 4th & 13rd & 4th downs · 77% expected +20% CHI MIN: 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.

  • Kyle Rudolph (MIN TE), out · 0.7 pts
  • Eric Kendricks (MIN LB), out · 0.5 pts
  • Kris Boyd (MIN CB), out (IR) · 0.3 pts
  • Jaylon Johnson (CHI DB), out · 0.7 pts
  • Bobby Massie (CHI OL), out (IR) · 0.5 pts
  • Buster Skrine (CHI DB), 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 84% · Vikings 16%

Final margin
Bears by 6
Luck in points
1.6 for the Bears
Luck-adjusted margin
Bears by 4.4
Replay with same day's form
Bears 39% · Vikings 61% 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 15 2020 games · Bears · Vikings

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