luckadjusted

Week 13 2019 · November 28, 2019

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

Bears at Lions, Week 13 2019: who deserved to win?

The Bears beat the Lions 24–20 and were the better team on the day: replayed with the same form, they win 7 of 10. The Lions had the bounces: judgment calls alone were worth 3.9 points to the Lions.

Before kickoff the Bears were 66% favorites. The biggest swing (Q4, 0:41 left): the Lions were stopped on 3rd & 9, worth 21 points of win probability to the Bears.

Final

Chicago Bears 24
Detroit Lions 20

November 28, 2019 · Ford Field · Closing line: Bears −5.5

Luck index +34 Bears lucky · −34 Lions

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, Lions win 3.

  1. 1 CHI 28 DET 3
  2. 2 CHI 24 DET 7
  3. 3 CHI 20 DET 7
  4. 4 CHI 19 DET 9
  5. 5 CHI 27 DET 20
  6. 6 CHI 27 DET 23
  7. 7 CHI 19 DET 17
  8. 8 CHI 24 DET 27
  9. 9 CHI 8 DET 16
  10. 10 CHI 14 DET 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 66% of them, Lions 34%, counting the 2% still level after regulation as half each. The line is what actually happened: Bears by 4.

Show as a table
Final margin in the replaysShare of replays
Bears by 17+17.0%
Bears by 9–1619.7%
Bears by 1–828.0%
Level after regulation2.2%
Lions by 1–817.9%
Lions by 9–1610.4%
Lions by 17+4.8%

Where the luck was

Take the luck out

The final margin was Bears by 4. Remove the luck, one kind at a time, and it becomes Bears by 3.0.

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.

  • M. Prater, 25 yds made · 98% expected
  • E. Pineiro, 30 yds made · 96% expected
  • M. Prater, 24 yds made · 99% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Lions’ chance of winning

As low as 0% and as high as 87%. 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 Lions were ahead in it, below while the Bears were.
#WhenWhat happenedWin probability forNext drive
1 Q1 11:12 The Lions converted 3rd & 103rd & 4th downs · 27% expected +21% DET DET: Touchdown
2 Q4 5:27 The Bears converted 3rd & 43rd & 4th downs · 44% expected +13% CHI CHI: Touchdown
3 Q4 2:52 The Bears converted 3rd & 53rd & 4th downs · 39% expected +20% CHI CHI: Touchdown
4 Q4 2:17 Roughing the Kicker on the Lions (Miles Killebrew), 15 yardsJudgment calls · 1 flag in 256 snaps before, position avg 1 per 465Neutral Zone Infraction on the Lions, 5 yardsPre-snap flags +18% CHI CHI: End of game
5 Q4 1:50 Offensive Holding on the Lions, 10 yards, wiping out the playJudgment calls +19% CHI CHI: End of game
6 Q4 0:58 Unnecessary Roughness on the Bears (Roquan Smith), 15 yardsJudgment calls · 1 flag in 650 snaps before, position avg 1 per 393 +17% DET DET: Turnover
7 Q4 0:41 The Lions were stopped on 3rd & 93rd & 4th downs · 29% expected +21% CHI DET: Turnover
8 Q4 0:36 The Lions were stopped on 4th & 223rd & 4th downs · 16% expected +16% CHI –

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.

  • Matthew Stafford (DET QB), out, replaced by d.blough · 6.3 pts
  • Rashaan Melvin (DET CB), out · 0.6 pts
  • Kerryon Johnson (DET RB), out (IR) · 0.2 pts
  • Bobby Massie (CHI T), out · 0.8 pts
  • Taylor Gabriel (CHI WR), out · 0.5 pts
  • Danny Trevathan (CHI LB), out · 0.4 pts
  • Trey Burton (CHI TE), out (IR) · 0.3 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 90% · Lions 10%

Final margin
Bears by 4
Luck in points
1.0 for the Bears
Luck-adjusted margin
Bears by 3.0
Replay with same day's form
Bears 66% · Lions 34% 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 13 2019 games · Bears · Lions

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