Week 18 2023 · January 7, 2024
Chiefs at Chargers, Week 18 2023: who deserved to win?
The Chiefs beat the Chargers 13–12, and it was no fluke: replayed with the way both teams actually played, the Chiefs win 9 of 10. The Chargers had the bounces: injuries alone were worth 6.5 points to the Chargers.
An off day for the Chargers: their offense played far below its usual level. In a fresh game against the Chiefs they would win 58% of the time; with this day’s form, 12%. The numbers
Before kickoff the Chargers were 60% favorites. The biggest swing (Q1, 5:14 left): Return touchdown by the Chiefs, worth 78 points of win probability to the Chiefs.
Final
 Kansas City Chiefs | 13 |
|---|---|
 Los Angeles Chargers | 12 |
Replay with same day's form
Luck index +12 Chiefs about even · −12 Chargers
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. Chiefs win 9, Chargers win 1.
- 1 KC 54 LAC 23
- 2 KC 30 LAC 7
- 3 KC 33 LAC 14
- 4 KC 24 LAC 8
- 5 KC 13 LAC 0
- 6 KC 16 LAC 6
- 7 KC 10 LAC 2
- 8 KC 25 LAC 20
- 9 KC 32 LAC 30
- 10 KC 25 LAC 31
Three other ways to ask
Each answers a different question, so none of them replaces the replay above.
Before kickoff
The closing betting line, turned into a probability. What everyone knew before the game.
Same teams, fresh 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.
Only coin-flips re-rolled
Every kick, fumble bounce, drop, conversion and judgment call redrawn; everything else fixed. The narrowest view of luck.
An off day for the Chargers
Their offense played far below its usual level. In a fresh game against the Chiefs they would win 58% of the time; with this day’s form, 12%.
Same teams, fresh game
Replay with same day's form
46 points apart for the Chargers: the gap is how differently this game went from what the two teams usually are.
| Unit | This game | Usual level | Better or worse than usual |
|---|---|---|---|
| Chiefs offenseEPA per play gained | −0.11 | +0.18 | worse by 0.29 |
| Chiefs defenseEPA per play allowed | −0.09 | +0.04 | better by 0.13 |
| Chargers offenseEPA per play gained | −0.09 | +0.06 | worse by 0.15 |
| Chargers defenseEPA per play allowed | −0.11 | +0.12 | better by 0.23 |
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
Chiefs win 88% of them, Chargers 12%, counting the 1% still level after regulation as half each. The line is what actually happened: Chiefs by 1.
Show as a table
| Final margin in the replays | Share of replays |
|---|---|
| Chiefs by 17+ | 41.5% |
| Chiefs by 9–16 | 25.6% |
| Chiefs by 1–8 | 20.8% |
| Level after regulation | 1.3% |
| Chargers by 1–8 | 7.5% |
| Chargers by 9–16 | 2.4% |
| Chargers by 17+ | 0.8% |
Where the luck was
Take the luck out
The final margin was Chiefs by 1. Remove the luck, one kind at a time, and it becomes Chiefs by 12.8.
The kicks
How likely each kicker was to make that kick (his own record, the distance and the weather), and what happened.
- H. Butker, 22 yds made · 100% expected
- C. Dicker, 49 yds made · 79% expected
- C. Dicker, 40 yds made · 90% expected
- C. Dicker, 43 yds made · 86% expected
- C. Dicker, 20 yds made · 100% expected
- H. Butker, 41 yds made · 89% expected
When it happened
Chargers’ chance of winning
As low as 0% and as high as 78%. Numbers mark the biggest luck moments, listed below.
| # | When | What happened | Win probability for | Next drive |
|---|---|---|---|---|
| 1 | Q1 5:14 | The Chargers were stopped on 3rd & 53rd & 4th downs · 31% expectedThe Chargers fumbled and the Chiefs recoveredFumble bounces · loose balls are close to 50/50Return touchdown by the ChiefsSpecial teams | +78% KC | LAC: Punt |
| 2 | Q2 1:36 | The Chiefs were stopped on 3rd & 103rd & 4th downs · 28% expectedThe Chiefs were intercepted on a well-placed throwInterceptions · 0% expected to stay out of the defense's hands | +13% LAC | KC: Punt |
| 3 | Q3 6:46 | The Chargers converted 3rd & 83rd & 4th downs · 30% expected | +16% LAC | LAC: Field goal |
| 4 | Q3 4:52 | The Chargers were stopped on 3rd & 63rd & 4th downs · 35% expected | +10% KC | LAC: Field goal |
| 5 | Q4 13:43 | The Chargers were stopped on 3rd & 73rd & 4th downs · 32% expectedA. Erickson dropped a catchable passDrops · 0 drops on 15 catchable balls before this | +11% KC | LAC: Punt |
| 6 | Q4 7:52 | The Chargers converted 4th & 63rd & 4th downs · 35% expected | +14% LAC | LAC: Field goal |
| 7 | Q4 3:26 | The Chiefs converted 3rd & 73rd & 4th downs · 34% expected | +17% KC | KC: Field goal |
| 8 | Q4 0:19 | The Chargers were stopped on 4th & 23rd & 4th downs · 58% expected | +18% KC | – |
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.
- Justin Herbert (LAC QB), out (IR), replaced by e.stick · 6.2 pts
- Keenan Allen (LAC WR), out · 1.1 pts
- Kenneth Murray (LAC LB), out · 0.5 pts
- Zion Johnson (LAC G), out · 0.5 pts
- Deane Leonard (LAC CB), out · 0.4 pts
- Will Clapp (LAC C), out (IR) · 0.3 pts
- Patrick Mahomes (KC QB), out, replaced by b.gabbert · 9.0 pts
- Trent McDuffie (KC CB), out · 1.4 pts
- Donovan Smith (KC T), out · 1.1 pts
- Travis Kelce (KC TE), out · 1.0 pts
- L'Jarius Sneed (KC CB), out · 0.7 pts
- Rashee Rice (KC WR), out · 0.6 pts
- Michael Danna (KC DE), out · 0.5 pts
- Nick Bolton (KC LB), out · 0.4 pts
- Bryan Cook (KC FS), out (IR) · 0.4 pts
- Isiah Pacheco (KC RB), 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
Chiefs 83% · Chargers 17%
- Final margin
- Chiefs by 1
- Luck in points
- 11.8 for the Chargers
- Luck-adjusted margin
- Chiefs by 12.8
- Replay with same day's form
- Chiefs 88% · Chargers 12% unchanged: why
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 18 2023 games · 
Chiefs · 
Chargers
More from Week 18 2023
- Steelers at Ravens PIT 17–10 · replay 17% for the winner
- Texans at Colts HOU 23–19 · replay 34% for the winner
- Falcons at Saints NO 48–17 · replay 60% for the winner
- Browns at Bengals CIN 31–14 · replay 93% for the winner
- Jaguars at Titans TEN 28–20 · replay 30% for the winner
- Vikings at Lions DET 30–20 · replay 72% for the winner
- Jets at Patriots NYJ 17–3 · replay 93% for the winner
- Buccaneers at Panthers TB 9–0 · replay 79% for the winner
- Bears at Packers GB 17–9 · replay 90% for the winner
- Cowboys at Commanders DAL 38–10 · replay 99% for the winner
- Broncos at Raiders LV 27–14 · replay 82% for the winner
- Rams at 49ers LA 21–20 · replay 58% for the winner
- Eagles at Giants NYG 27–10 · replay 51% for the winner
- Seahawks at Cardinals SEA 21–20 · replay 43% for the winner
- Bills at Dolphins BUF 21–14 · replay 52% for the winner