Week 17 2020 · January 3, 2021
No FTN charting for this game (drops and interception-worthy throws are not modelled).
Chargers at Chiefs, Week 17 2020: who deserved to win?
The Chargers beat the Chiefs 38–21, and the replays lean their way: with the same day's form, they win 8 of 10.
Before kickoff the Chargers were 70% favorites. The biggest swing (Q2, 1:56 left): the Chargers were stopped on 4th & 2, worth 11 points of win probability to the Chiefs.
Final
 Los Angeles Chargers | 38 |
|---|---|
 Kansas City Chiefs | 21 |
Replay with same day's form
Luck index +24 Chargers about even · −24 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 8, Chiefs win 2.
- 1 LAC 32 KC 7
- 2 LAC 35 KC 17
- 3 LAC 31 KC 17
- 4 LAC 38 KC 27
- 5 LAC 39 KC 31
- 6 LAC 23 KC 17
- 7 LAC 23 KC 20
- 8 LAC 23 KC 21
- 9 LAC 19 KC 23
- 10 LAC 21 KC 34
Your call
Did the Chargers earn it, or get lucky?
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.
How 4,000 replays ended
Chargers win 76% of them, Chiefs 24%, counting the 3% still level after regulation as half each. The line is what actually happened: Chargers by 17.
Show as a table
| Final margin in the replays | Share of replays |
|---|---|
| Chargers by 17+ | 26.1% |
| Chargers by 9–16 | 22.2% |
| Chargers by 1–8 | 27.7% |
| Level after regulation | 3.1% |
| Chiefs by 1–8 | 12.5% |
| Chiefs by 9–16 | 6.4% |
| Chiefs by 17+ | 2.1% |
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.
Penalties: Chargers 4 for 23 yards, Chiefs 5 for 69 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 half toward luck; pre-snap fouls, which repeat, don’t count. How calls are valued
| When | Flag | Win probability for |
|---|---|---|
| Q1 11:45 | Face Mask on the Chargers (Linval Joseph), 3 yards | +2% KC +0.7 pts |
| Q1 3:47 | Defensive Offside on the Chargers (Jerry Tillery), 5 yards · pre-snap | 0% KC +0.3 pts |
| Q2 8:52 | Defensive Offside on the Chargers, 5 yards, wiping out the play · pre-snap | +7% KC +1.5 pts |
| Q2 0:56 | Lowering the Head to Initiate Contact on the Chiefs (Juan Thornhill), 15 yards | +1% LAC +1.4 pts |
| Q2 0:51 | Defensive Pass Interference on the Chiefs (Thakarius Keyes), 21 yards | +4% LAC +2.1 pts |
| Q3 13:01 | Offensive Holding on the Chargers (Tyron Johnson), 10 yards | 0% KC +0.9 pts |
| Q3 11:21 | Offensive Holding on the Chiefs (Rashad Fenton), 8 yards | +2% LAC +0.7 pts |
| Q4 7:23 | Offensive Pass Interference on the Chiefs, 10 yards, wiping out the play | +1% LAC +2.2 pts |
| Q4 4:41 | Face Mask on the Chiefs, 15 yards | 0% LAC +1.8 pts |
Chargers penalties, every game · Chiefs penalties, every game · All teams, 2020
When it happened
Chiefs’ chance of winning
As low as 0% and as high as 73%. Numbers mark the biggest luck moments, listed below.
| # | When | What happened | Win probability for | Next drive |
|---|---|---|---|---|
| 1 | Q1 13:36 | The Chiefs converted 3rd & 93rd & 4th downs · 34% expected | +8% KC | KC: Touchdown |
| 2 | Q2 15:00 | The Chiefs converted 3rd & 73rd & 4th downs · 39% expected | +6% KC | KC: Touchdown |
| 3 | Q2 12:06 | The Chiefs fumbled and the Chargers recoveredFumble bounces · loose balls are close to 50/50 | +6% LAC | KC: Punt |
| 4 | Q2 8:52 | Defensive Offside on the Chargers, 5 yards, wiping out the playPre-snap flags | +7% KC | KC: Punt |
| 5 | Q2 7:00 | The Chargers converted 3rd & 123rd & 4th downs · 29% expected | +8% LAC | LAC: Turnover on downs |
| 6 | Q2 6:04 | The Chargers converted 3rd & 103rd & 4th downs · 33% expected | +8% LAC | LAC: Turnover on downs |
| 7 | Q2 1:56 | The Chargers were stopped on 4th & 23rd & 4th downs · 59% expected | +11% KC | LAC: Touchdown |
| 8 | Q3 4:30 | The Chiefs were stopped on 3rd & 13rd & 4th downs · 78% expected | +8% LAC | KC: Turnover on downs |
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 Mahomes (KC QB), out, replaced by c.henne · 8.8 pts
- Tyreek Hill (KC WR), out · 1.6 pts
- Tyrann Mathieu (KC S), out · 0.8 pts
- Sammy Watkins (KC WR), out · 0.7 pts
- Mike Remmers (KC T), out · 0.6 pts
- Anthony Hitchens (KC LB), out (IR) · 0.3 pts
- Clyde Edwards-Helaire (KC RB), out · 0.1 pts
- Sam Tevi (LAC T), out · 1.1 pts
- Hunter Henry (LAC TE), out (IR) · 1.0 pts
- Joey Bosa (LAC DE), out · 1.0 pts
- Keenan Allen (LAC WR), out (IR) · 1.0 pts
- Casey Hayward (LAC CB), out (IR) · 1.0 pts
- Melvin Ingram (LAC DE), out (IR) · 0.8 pts
- Bryan Bulaga (LAC T), out · 0.6 pts
- Rayshawn Jenkins (LAC S), out · 0.4 pts
- Kyzir White (LAC LB), out (IR) · 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 100% · Chiefs 0%
- Final margin
- Chargers by 17
- Luck in points
- 5.8 for the Chargers
- Luck-adjusted margin
- Chargers by 11.2
- Replay with same day's form
- Chargers 76% · Chiefs 24% 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 (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 2020 games · 
Chargers · 
Chiefs
More from Week 17 2020
- Falcons at Buccaneers TB 44–27 · replay 98% for the winner
- Ravens at Bengals BAL 38–3 · replay 96% for the winner
- Cowboys at Giants NYG 23–19 · replay 50% for the winner
- Dolphins at Bills BUF 56–26 · replay 96% for the winner
- Vikings at Lions MIN 37–35 · replay 45% for the winner
- Jets at Patriots NE 28–14 · replay 57% for the winner
- Steelers at Browns CLE 24–22 · replay 71% for the winner
- Cardinals at Rams LA 18–7 · replay 47% for the winner
- Packers at Bears GB 35–16 · replay 94% for the winner
- Jaguars at Colts IND 28–14 · replay 97% for the winner
- Raiders at Broncos LV 32–31 · replay 69% for the winner
- Saints at Panthers NO 33–7 · replay 87% for the winner
- Seahawks vs 49ers SEA 26–23 · replay 78% for the winner
- Titans at Texans TEN 41–38 · replay 40% for the winner
- Washington at Eagles WAS 20–14 · replay 62% for the winner