luckadjusted

Week 2 2019 · September 15, 2019

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

Bears at Broncos, Week 2 2019: who deserved to win?

The Bears stole one. They beat the Broncos 16–14, but replayed with the way both teams actually played, the Broncos win 9 of 10. Luck ran their way: judgment calls alone were worth 3.8 points to the Bears.

The Bears won on an off day: they played far below what the matchup promised. In a fresh game against the Broncos they would win 57% of the time; with this day’s form, 10%. The numbers

Before kickoff the Bears were 59% favorites. The biggest swing (Q4, 0:09 left): the Bears converted 4th & 15, worth 36 points of win probability to the Bears.

Final

Chicago Bears 16
Denver Broncos 14

September 15, 2019 · Empower Field at Mile High · Closing line: Bears −3

Luck index +90 Bears very lucky · −90 Broncos

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 1, Broncos win 9.

  1. 1 CHI 23 DEN 17
  2. 2 CHI 7 DEN 10
  3. 3 CHI 7 DEN 12
  4. 4 CHI 13 DEN 21
  5. 5 CHI 6 DEN 16
  6. 6 CHI 10 DEN 23
  7. 7 CHI 3 DEN 19
  8. 8 CHI 3 DEN 23
  9. 9 CHI 10 DEN 33
  10. 10 CHI 0 DEN 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.

The Bears won on an off day

They played far below what the matchup promised. In a fresh game against the Broncos they would win 57% of the time; with this day’s form, 10%.

47 points apart for the Bears: the gap is how differently this game went from what the two teams usually are.

UnitThis gameUsual levelBetter or worse than usual
Bears offenseEPA per play gained +0.02 +0.12 worse by 0.10
Bears defenseEPA per play allowed +0.11 +0.04 worse by 0.08
Broncos offenseEPA per play gained +0.11 +0.07 better by 0.04
Broncos defenseEPA per play allowed +0.02 +0.17 better by 0.15

EPA (expected points added) per play on competitive snaps, turnovers left out because they are valued as luck. Usual level: the team’s earlier games this season plus half of last season, pulled toward the league average. One team’s defense and the other team’s offense are the same snaps, so one game can’t fully say whose day it was; it shows how far this one was from both teams’ norms.

How 4,000 replays ended

Bears win 10% of them, Broncos 90%, counting the 1% still level after regulation as half each. The line is what actually happened: Bears by 2.

Show as a table
Final margin in the replaysShare of replays
Bears by 17+0.5%
Bears by 9–161.6%
Bears by 1–87.4%
Level after regulation1.4%
Broncos by 1–820.5%
Broncos by 9–1625.9%
Broncos by 17+42.8%

Where the luck was

Take the luck out

The final margin was Bears by 2. Remove the luck, one kind at a time, and it becomes Broncos by 4.9.

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.

  • B. McManus, 43 yds made · 84% expected
  • E. Pineiro, 40 yds made · 88% expected
  • E. Pineiro, 52 yds made · 70% expected
  • B. McManus, 32 yds made · 95% expected
  • E. Pineiro, 53 yds made · 69% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Broncos’ chance of winning

As low as 0% and as high as 81%. 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 Broncos were ahead in it, below while the Bears were.
#WhenWhat happenedWin probability forNext drive
1 Q2 11:43 The Broncos converted 3rd & 153rd & 4th downs · 21% expected +8% DEN DEN: Punt
2 Q4 14:01 Offensive Holding on the Broncos, 10 yardsJudgment calls +8% CHI CHI: Punt
3 Q4 13:56 Roughing the Passer on the Bears (Eddie Goldman), 15 yardsJudgment calls · 0 flags in 35 snaps before, position avg 1 per 411 +10% DEN DEN: Field goal
4 Q4 4:51 The Broncos were stopped on 3rd & 23rd & 4th downs · 52% expected +28% CHI DEN: Touchdown
5 Q4 2:25 The Broncos converted 4th & 103rd & 4th downs · 27% expected +8% DEN DEN: Touchdown
6 Q4 1:02 The Broncos converted 4th & 33rd & 4th downs · 51% expected +9% DEN DEN: Touchdown
7 Q4 0:09 The Bears converted 4th & 153rd & 4th downs · 20% expectedOffensive Too Many Men on Field on the Bears, 5 yardsPre-snap flags +36% CHI CHI: Field goal
8 Q4 0:01 E. Pineiro made 53-yard field goalKicks · 69% expected for him, 1 of 1 from 45+ before +33% 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.

  • Tim Patrick (DEN WR), out (IR) · 0.4 pts
  • Todd Davis (DEN LB), out · 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 30% · Broncos 70%

Final margin
Bears by 2
Luck in points
6.9 for the Bears
Luck-adjusted margin
Broncos by 4.9
Replay with same day's form
Bears 10% · Broncos 90% 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 2 2019 games · Bears · Broncos

More from Week 2 2019