luckadjusted

Week 15 2023 · December 17, 2023

Bears at Browns, Week 15 2023: who deserved to win?

The Browns beat the Bears 20–17, and it was no fluke: replayed with the way both teams actually played, the Browns win 9 of 10. The Bears had the bounces: judgment calls alone were worth 2.5 points to the Bears.

An off day for the Bears: their offense played far below its usual level. In a fresh game against the Browns they would win 44% of the time; with this day’s form, 12%. The numbers

Before kickoff the Browns were 59% favorites. The biggest swing (Q4, 0:05 left): the Bears were intercepted on a well-placed throw, worth 99 points of win probability to the Browns.

Final

Chicago Bears 17
Cleveland Browns 20

December 17, 2023 · FirstEnergy Stadium · Closing line: Browns −3

Luck index +12 Browns about even · −12 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. Bears win 1, Browns win 9.

  1. 1 CHI 22 CLE 13
  2. 2 CHI 20 CLE 22
  3. 3 CHI 9 CLE 14
  4. 4 CHI 15 CLE 23
  5. 5 CHI 10 CLE 21
  6. 6 CHI 13 CLE 28
  7. 7 CHI 16 CLE 33
  8. 8 CHI 6 CLE 28
  9. 9 CHI 17 CLE 43
  10. 10 CHI 10 CLE 43

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.

An off day for the Bears

Their offense played far below its usual level. In a fresh game against the Browns they would win 44% of the time; with this day’s form, 12%.

32 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 −0.30 +0.09 worse by 0.40
Bears defenseEPA per play allowed −0.05 +0.14 better by 0.19
Browns offenseEPA per play gained −0.05 +0.04 worse by 0.09
Browns defenseEPA per play allowed −0.30 +0.04 better by 0.34

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 12% of them, Browns 88%, counting the 1% still level after regulation as half each. The line is what actually happened: Browns by 3.

Show as a table
Final margin in the replaysShare of replays
Bears by 17+1.3%
Bears by 9–162.5%
Bears by 1–87.3%
Level after regulation0.9%
Browns by 1–815.2%
Browns by 9–1619.3%
Browns by 17+53.4%

Where the luck was

Take the luck out

The final margin was Browns by 3. Remove the luck, one kind at a time, and it becomes Browns 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.

  • C. Santos, 41 yds made · 83% expected
  • D. Hopkins, 33 yds made · 93% expected
  • D. Hopkins, 34 yds made · 92% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Browns’ chance of winning

As low as 10% and as high as 100%. 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 Browns were ahead in it, below while the Bears were.
#WhenWhat happenedWin probability forNext drive
1 Q1 4:05 The Bears converted 3rd & 23rd & 4th downs · 58% expected +8% CHI CHI: Punt
2 Q2 8:49 The Browns converted 3rd & 73rd & 4th downs · 29% expected +10% CLE CLE: Touchdown
3 Q2 0:04 The Bears were stopped on 4th & 43rd & 4th downs · 43% expectedThe Bears were intercepted on a well-placed throwInterceptions · 0% expected to stay out of the defense's hands +21% CLE CHI: Punt
4 Q3 14:01 The Browns were intercepted on a well-placed throwInterceptions · 0% expected to stay out of the defense's handsReturn touchdown by the BearsSpecial teams +40% CHI CLE: Punt
5 Q3 2:39 The Bears fumbled and the Browns recoveredFumble bounces · loose balls are close to 50/50 +9% CLE CHI: Turnover on downs
6 Q4 15:00 The Bears were stopped on 4th & 13rd & 4th downs · 71% expected +8% CLE CHI: Punt
7 Q4 0:56 The Browns converted 3rd & 153rd & 4th downs · 17% expected +20% CLE CLE: Field goal
8 Q4 0:05 The Bears were stopped on 3rd & 103rd & 4th downs · 25% expectedThe Bears were intercepted on a well-placed throwInterceptions · 0% expected to stay out of the defense's hands +99% CLE –

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.

  • Grant Delpit (CLE SS), out (IR) · 0.5 pts
  • Juan Thornhill (CLE FS), out · 0.5 pts
  • Ethan Pocic (CLE C), out · 0.4 pts
  • Dawand Jones (CLE T), out (IR) · 0.4 pts
  • Anthony Walker (CLE LB), out · 0.2 pts
  • Ogbonnia Okoronkwo (CLE DE), out · 0.2 pts
  • Yannick Ngakoue (CHI DE), out (IR) · 0.8 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 38% · Browns 62%

Final margin
Browns by 3
Luck in points
none
Luck-adjusted margin
Browns by 3.0
Replay with same day's form
Bears 12% · Browns 88% 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; injuries from snap counts and injury reports.

Methodology and validation · All Week 15 2023 games · Bears · Browns

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