luckadjusted

Week 1 2024 · September 8, 2024

Titans at Bears, Week 1 2024: who deserved to win?

The Bears beat the Titans 24–17, but the Titans played well enough to win it: they take 8 of 10 replays with the same day's form. Luck ran their way: 3rd & 4th downs alone were worth 18 points of win probability to the Bears.

The Bears won on an off day: their offense played far below its usual level. In a fresh game against the Titans they would win 60% of the time; with this day’s form, 22%. The numbers

Before kickoff the Bears were 62% favorites. The biggest swing (Q4, 7:45 left): Return touchdown by the Bears, worth 96 points of win probability to the Bears.

Final

Tennessee Titans 17
Chicago Bears 24

September 8, 2024 · Soldier Field · Closing line: Bears −4

Luck index +78 Bears very lucky · −78 Titans

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. Titans win 8, Bears win 2.

  1. 1 TEN 39 CHI 14
  2. 2 TEN 22 CHI 3
  3. 3 TEN 26 CHI 10
  4. 4 TEN 22 CHI 10
  5. 5 TEN 13 CHI 3
  6. 6 TEN 20 CHI 14
  7. 7 TEN 12 CHI 9
  8. 8 TEN 19 CHI 17
  9. 9 TEN 5 CHI 9
  10. 10 TEN 6 CHI 20

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

Their offense played far below its usual level. In a fresh game against the Titans they would win 60% of the time; with this day’s form, 22%.

38 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
Titans offenseEPA per play gained −0.05 +0.05 worse by 0.10
Titans defenseEPA per play allowed −0.25 +0.08 better by 0.33
Bears offenseEPA per play gained −0.25 +0.08 worse by 0.33
Bears defenseEPA per play allowed −0.05 +0.09 better by 0.13

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

Titans win 78% of them, Bears 22%, counting the 2% still level after regulation as half each. The line is what actually happened: Bears by 7.

Show as a table
Final margin in the replaysShare of replays
Titans by 17+28.3%
Titans by 9–1623.1%
Titans by 1–825.9%
Level after regulation2.4%
Bears by 1–811.7%
Bears by 9–166.8%
Bears by 17+1.9%

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 +2.9 points to the Bears: the final margin was Bears by 7, without the luck Bears by 4.1. 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.

  • N. Folk, 40 yds made · 88% expected
  • C. Santos, 24 yds made · 99% expected
  • C. Santos, 50 yds made · 71% expected
  • C. Santos, 48 yds made · 75% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Titans 8 for 50 yards, Bears 7 for 55 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 toward luck, pre-snap fouls mostly don’t. How calls are valued

WhenFlagWin probability for
Q1 11:50 False Start on the Titans, 5 yards · pre-snap +2% CHI +0.6 pts
Q1 7:42 Defensive Too Many Men on Field on the Titans, 5 yards · pre-snap +1% CHI +0.5 pts
Q1 5:33 Offensive Holding on the Bears, 10 yards +3% TEN +0.9 pts
Q2 12:19 Offensive Holding on the Bears, 10 yards +1% TEN +0.9 pts
Q2 12:03 False Start on the Titans, 5 yards · pre-snap +1% CHI +0.8 pts
Q2 4:40 Defensive Offside on the Bears (Montez Sweat), 5 yards · pre-snap +1% TEN +0.9 pts
Q2 4:33 Illegal Formation on the Titans, 5 yards · pre-snap +2% CHI +1.0 pts
Q2 4:08 False Start on the Titans (Chigoziem Okonkwo), 5 yards · pre-snap +1% CHI +0.5 pts
Q3 13:18 Delay of Game on the Bears, 5 yards · pre-snap +1% TEN +0.7 pts
Q3 13:13 False Start on the Bears, 5 yards · pre-snap 0% TEN +0.3 pts
Q3 9:02 Offensive Holding on the Titans, 10 yards +2% CHI +1.3 pts
Q3 7:16 Illegal Block Above the Waist on the Bears (Daniel Hardy), 10 yards +2% TEN +1.0 pts
Q3 6:12 Illegal Block Above the Waist on the Titans (Nick Westbrook-Ikhine), 10 yards 0% CHI +0.9 pts
Q4 15:00 Neutral Zone Infraction on the Titans (Harold Landry), 5 yards · pre-snap +2% CHI +1.5 pts
Q4 11:40 Offensive Holding on the Bears, 10 yards +9% TEN +1.4 pts

Titans penalties, every game · Bears penalties, every game · All teams, 2024

When it happened

Bears’ chance of winning

As low as 8% 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 Bears were ahead in it, below while the Titans were.
#WhenWhat happenedWin probability forNext drive
1 Q1 8:17 The Bears converted 4th & 33rd & 4th downs · 49% expected +9% CHI CHI: Punt
2 Q2 12:00 The Titans converted 3rd & 153rd & 4th downs · 20% expected +8% TEN TEN: Touchdown
3 Q3 9:14 Blocked punt by the BearsSpecial teams +13% CHI CHI: Opp touchdown
4 Q4 11:54 The Titans were stopped on 3rd & 63rd & 4th downs · 36% expectedThe Titans fumbled and the Bears recoveredFumble bounces · loose balls are close to 50/50 +35% CHI TEN: Opp touchdown
5 Q4 11:40 Offensive Holding on the Bears, 10 yardsJudgment calls +9% TEN TEN: Opp touchdown
6 Q4 9:57 C. Santos made 48-yard field goalKicks · 75% expected for him, 28 of 39 from 45+ before +7% CHI CHI: Opp touchdown
7 Q4 7:45 The Titans were stopped on 3rd & 63rd & 4th downs · 36% expectedThe Titans threw an interception-worthy pass, and it was pickedInterceptions · 49% expected to stay out of the defense's handsReturn touchdown by the BearsSpecial teams +96% CHI TEN: Punt
8 Q4 1:15 The Titans were stopped on 4th & 103rd & 4th downs · 26% expectedThe Titans threw an interception-worthy pass, and it was pickedInterceptions · 49% expected to stay out of the defense's hands +14% 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.

  • Patrick Scales (CHI LS), out (IR) · 0.1 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

Titans 26% · Bears 74%

Final margin
Bears by 7
Luck in points
2.9 for the Bears
Luck-adjusted margin
Bears by 4.1
Replay with same day's form
Titans 78% · Bears 22% 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 1 2024 games · Titans · Bears

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