luckadjusted

Week 17 2021 · January 2, 2022

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

Giants at Bears, Week 17 2021: who deserved to win?

The Bears beat the Giants 29–3, and it was no fluke: replayed with the way both teams actually played, the Bears win 9 of 10. The Giants had the bounces: judgment calls alone were worth 2.3 points to the Giants.

Before kickoff the Bears were 70% favorites. The biggest swing (Q1, 14:54 left): the Giants fumbled and the Bears recovered, worth 11 points of win probability to the Bears.

Final

New York Giants 3
Chicago Bears 29

January 2, 2022 · Soldier Field · Closing line: Bears −7

Luck index +10 Bears about even · −10 Giants

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. Giants win 1, Bears win 9.

  1. 1 NYG 22 CHI 16
  2. 2 NYG 20 CHI 23
  3. 3 NYG 14 CHI 20
  4. 4 NYG 13 CHI 21
  5. 5 NYG 14 CHI 24
  6. 6 NYG 6 CHI 19
  7. 7 NYG 10 CHI 26
  8. 8 NYG 7 CHI 27
  9. 9 NYG 10 CHI 33
  10. 10 NYG 0 CHI 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

Giants win 10% of them, Bears 90%, counting the 2% still level after regulation as half each. The line is what actually happened: Bears by 26.

Show as a table
Final margin in the replaysShare of replays
Giants by 17+0.4%
Giants by 9–161.8%
Giants by 1–86.3%
Level after regulation2.0%
Bears by 1–817.7%
Bears by 9–1623.6%
Bears by 17+48.2%

Where the luck was

Take the luck out

The final margin was Bears by 26. Remove the luck, one kind at a time, and it becomes Bears by 19.2.

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.

  • G. Gano, 38 yds made · 87% expected
  • C. Santos, 21 yds made · 98% expected
  • C. Santos, 44 yds made · 75% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Bears’ chance of winning

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 Giants were.
#WhenWhat happenedWin probability forNext drive
1 Q1 14:54 The Giants fumbled and the Bears recoveredFumble bounces · loose balls are close to 50/50 +11% CHI NYG: Turnover
2 Q1 11:58 The Giants were stopped on 3rd & 23rd & 4th downs · 58% expected +5% CHI NYG: Punt
3 Q1 10:31 The Bears converted 3rd & 93rd & 4th downs · 26% expected +5% CHI CHI: Touchdown
4 Q1 8:14 The Bears converted 4th & 23rd & 4th downs · 48% expected +4% CHI CHI: Touchdown
5 Q1 5:23 The Giants were stopped on 3rd & 73rd & 4th downs · 32% expected +2% CHI NYG: Punt
6 Q2 10:26 The Giants converted 3rd & 43rd & 4th downs · 43% expected +3% NYG NYG: Field goal
7 Q2 5:02 The Bears converted 3rd & 23rd & 4th downs · 56% expected +2% CHI CHI: Field goal
8 Q2 1:04 C. Santos made 21-yard field goalKicks · 98% expected for him +3% NYG 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.

  • Duke Shelley (CHI CB), out · 0.2 pts
  • DeAndre Houston-Carson (CHI FS), out (IR) · 0.2 pts
  • Daniel Jones (NYG QB), out (IR), replaced by m.glennon · 1.9 pts
  • Dexter Lawrence (NYG DE), out (IR) · 0.9 pts
  • Darius Slayton (NYG WR), out (IR) · 0.7 pts
  • Sterling Shepard (NYG WR), out (IR) · 0.5 pts
  • Billy Price (NYG C), out · 0.4 pts
  • Kadarius Toney (NYG WR), out · 0.3 pts
  • Darnay Holmes (NYG CB), out (IR) · 0.2 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

Giants 0% · Bears 100%

Final margin
Bears by 26
Luck in points
6.8 for the Bears
Luck-adjusted margin
Bears by 19.2
Replay with same day's form
Giants 10% · Bears 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 17 2021 games · Giants · Bears

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