luckadjusted

Week 15 2025 · December 14, 2025

Chargers at Chiefs, Week 15 2025: who deserved to win?

The Chargers beat the Chiefs 16–13, but it was a coin flip: replayed with the way both teams played, the Chargers win 5 of 10. Luck ran their way: kicks alone were worth 11 points of win probability to the Chargers.

Before kickoff the Chiefs were 66% favorites. The biggest swing (Q4, 12:47 left): the Chiefs were stopped on 3rd & 12, worth 27 points of win probability to the Chargers.

Final

Los Angeles Chargers 16
Kansas City Chiefs 13

December 14, 2025 · GEHA Field at Arrowhead Stadium · Closing line: Chiefs −5.5

Luck index +47 Chargers lucky · −47 Chiefs

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. Chargers win 5, Chiefs win 5.

  1. 1 LAC 38 KC 17
  2. 2 LAC 30 KC 17
  3. 3 LAC 24 KC 16
  4. 4 LAC 19 KC 14
  5. 5 LAC 20 KC 17
  6. 6 LAC 26 KC 28
  7. 7 LAC 11 KC 15
  8. 8 LAC 21 KC 30
  9. 9 LAC 16 KC 29
  10. 10 LAC 13 KC 31

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

Chargers win 53% of them, Chiefs 47%, counting the 6% still level after regulation as half each. The line is what actually happened: Chargers by 3.

Show as a table
Final margin in the replaysShare of replays
Chargers by 17+9.8%
Chargers by 9–1615.3%
Chargers by 1–823.6%
Level after regulation6.1%
Chiefs by 1–820.9%
Chiefs by 9–1615.2%
Chiefs by 17+9.0%

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 +4.1 points to the Chargers: the final margin was Chargers by 3, without the luck Chiefs by 1.1. 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.

  • C. Dicker, 49 yds made · 79% expected
  • H. Butker, 27 yds made · 99% expected
  • H. Butker, 47 yds made · 80% expected
  • C. Dicker, 23 yds made · 100% expected
  • C. Dicker, 49 yds made · 79% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Chargers 5 for 50 yards, Chiefs 9 for 64 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 14:23 Low Block on the Chargers (Derwin James), 15 yards +4% KC +1.1 pts
Q1 6:06 Defensive Offside on the Chiefs (Chris Jones), 5 yards · pre-snap 0% LAC +0.2 pts
Q1 0:52 Illegal Use of Hands on the Chiefs (Nohl Williams), 5 yards +1% LAC +0.8 pts
Q2 4:34 Defensive Offside on the Chiefs (Chris Jones), 5 yards · pre-snap +5% LAC +1.2 pts
Q2 2:57 Offensive Holding on the Chiefs (Joshua Williams), 6 yards +2% LAC +0.4 pts
Q2 1:43 Defensive Too Many Men on Field on the Chargers, 5 yards · pre-snap 0% LAC 0.0 pts
Q3 14:56 Defensive Holding on the Chiefs (Nohl Williams), 5 yards +1% LAC +0.3 pts
Q3 13:32 Offensive Holding on the Chargers, 10 yards +8% KC +1.2 pts
Q3 5:03 False Start on the Chargers (KeAndre Lambert-Smith), 5 yards · pre-snap 0% LAC +0.2 pts
Q4 14:10 Illegal Blindside Block on the Chiefs (JuJu Smith-Schuster), 15 yards +6% LAC +1.1 pts
Q4 13:46 Disqualification on the Chargers (Tony Jefferson), 15 yards +8% KC +1.8 pts
Q4 5:29 Offensive Holding on the Chiefs (Nohl Williams), 8 yards +6% LAC +0.7 pts
Q4 2:00 Offensive Holding on the Chiefs, 10 yards +8% LAC +1.0 pts
Q4 0:20 Delay of Game on the Chiefs, 5 yards · pre-snap +6% LAC +0.5 pts

Chargers penalties, every game · Chiefs penalties, every game · All teams, 2025

When it happened

Chiefs’ chance of winning

As low as 0% and as high as 82%. 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 Chiefs were ahead in it, below while the Chargers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 11:37 The Chiefs converted 3rd & 113rd & 4th downs · 26% expected +8% KC KC: Touchdown
2 Q2 11:09 The Chargers were stopped on 3rd & 113rd & 4th downs · 28% expectedThe Chargers threw an interception-worthy pass, and it was pickedInterceptions · 48% expected to stay out of the defense's hands +9% KC LAC: Punt
3 Q2 0:11 The Chargers converted 3rd & 33rd & 4th downs · 53% expected +8% LAC LAC: Touchdown
4 Q3 0:57 C. Dicker made 49-yard field goalKicks · 79% expected for him, 41 of 48 from 45+ before +9% LAC LAC: Punt
5 Q4 13:46 Disqualification on the Chargers (Tony Jefferson), 15 yardsJudgment calls · 3 flags in 1402 snaps before, position avg 1 per 467 +8% KC KC: Turnover
6 Q4 12:47 The Chiefs were stopped on 3rd & 123rd & 4th downs · 24% expectedThe Chiefs threw an interception-worthy pass, and it was pickedInterceptions · 52% expected to stay out of the defense's hands +27% LAC KC: Turnover
7 Q4 2:00 Offensive Holding on the Chiefs, 10 yardsJudgment calls +8% LAC LAC: End of game
8 Q4 0:20 The Chiefs threw an interception-worthy pass, and it was pickedInterceptions · 53% expected to stay out of the defense's handsDelay of Game on the Chiefs, 5 yardsPre-snap flags +27% LAC KC: End of game

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.

  • Trent McDuffie (KC CB), out · 1.4 pts
  • Jawaan Taylor (KC T), out · 0.9 pts
  • Josh Simmons (KC T), out (IR) · 0.7 pts
  • Trey Smith (KC G), out · 0.5 pts
  • Quentin Johnston (LAC WR), out · 0.6 pts
  • Joe Alt (LAC T), out (IR) · 0.5 pts
  • Elijah Molden (LAC DB), out · 0.4 pts
  • Trey Pipkins (LAC G), 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

Chargers 56% · Chiefs 44%

Final margin
Chargers by 3
Luck in points
4.1 for the Chargers
Luck-adjusted margin
Chiefs by 1.1
Replay with same day's form
Chargers 53% · Chiefs 47% 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 2025 games · Chargers · Chiefs

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