Week 2 2020 · September 20, 2020
No FTN charting for this game (drops and interception-worthy throws are not modelled).
Chiefs at Chargers, Week 2 2020: who deserved to win?
The Chiefs beat the Chargers 23–20, but it was a coin flip: replayed with the way both teams played, the Chiefs win 4 of 10. Luck ran their way: 3rd & 4th downs alone were worth 17 points of win probability to the Chiefs.
The Chiefs won on an off day: they played far below what the matchup promised. In a fresh game against the Chargers they would win 72% of the time; with this day’s form, 40%. The numbers
Before kickoff the Chiefs were 74% favorites. The game turned on a luck play (QOT, 2:00 left): H. Butker made 58-yard field goal, worth 47 points of win probability to the Chiefs. The biggest single swing (Q4, 1:14 left): Offensive Holding on the Chiefs, 10 yards, wiping out the play.
Final (OT)
 Kansas City Chiefs | 23 |
|---|---|
 Los Angeles Chargers | 20 |
Replay with same day's form
Luck index +60 Chiefs lucky · −60 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 4, Chargers win 6.
- 1 KC 44 LAC 25
- 2 KC 22 LAC 12
- 3 KC 26 LAC 20
- 4 KC 38 LAC 36
- 5 KC 31 LAC 33
- 6 KC 26 LAC 30
- 7 KC 35 LAC 44
- 8 KC 6 LAC 18
- 9 KC 24 LAC 41
- 10 KC 7 LAC 33
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.
The Chiefs won on an off day
They played far below what the matchup promised. In a fresh game against the Chargers they would win 72% of the time; with this day’s form, 40%.
Same teams, fresh game
Replay with same day's form
32 points apart for the Chiefs: 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 | +0.12 | +0.21 | worse by 0.09 |
| Chiefs defenseEPA per play allowed | +0.09 | +0.11 | better by 0.03 |
| Chargers offenseEPA per play gained | +0.09 | +0.11 | worse by 0.03 |
| Chargers defenseEPA per play allowed | +0.12 | +0.11 | worse by 0.01 |
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 40% of them, Chargers 60%, counting the 3% still level after regulation as half each. The line is what actually happened: Chiefs by 3.
Show as a table
| Final margin in the replays | Share of replays |
|---|---|
| Chiefs by 17+ | 7.1% |
| Chiefs by 9–16 | 12.3% |
| Chiefs by 1–8 | 20.0% |
| Level after regulation | 2.6% |
| Chargers by 1–8 | 26.5% |
| Chargers by 9–16 | 16.2% |
| Chargers by 17+ | 15.3% |
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.
The kicks
How likely each kicker was to make that kick (his own record, the distance and the weather), and what happened.
- M. Badgley, 41 yds made · 87% expected
- H. Butker, 58 yds made · 62% expected
- M. Badgley, 23 yds made · 99% expected
- H. Butker, 30 yds made · 97% expected
- H. Butker, 58 yds made · 63% expected
- Extra point missed · 80% expected
Penalties: Chiefs 11 for 90 yards, Chargers 6 for 40 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
| When | Flag | Win probability for |
|---|---|---|
| Q1 3:39 | Defensive Offside on the Chiefs (Chris Jones), 5 yards · pre-snap | +1% LAC +0.3 pts |
| Q1 1:28 | Offensive Holding on the Chiefs (Sammy Watkins), 10 yards | +3% LAC +1.1 pts |
| Q2 8:51 | Offensive Holding on the Chiefs, 10 yards | +3% LAC +0.9 pts |
| Q2 3:21 | Offensive Holding on the Chargers, 10 yards | +4% KC +1.2 pts |
| Q2 1:19 | Offensive Holding on the Chiefs, 10 yards, wiping out the play | +9% LAC +2.3 pts |
| Q2 1:11 | Defensive Offside on the Chargers (Joey Bosa), 5 yards · pre-snap | +1% KC +0.4 pts |
| Q2 0:04 | Delay of Game on the Chargers (Justin Herbert), 5 yards · pre-snap | +2% KC +0.3 pts |
| Q2 0:04 | Defensive Offside on the Chiefs (Taco Charlton), 5 yards, wiping out the play · pre-snap | +7% LAC +1.7 pts |
| Q3 5:03 | False Start on the Chiefs (Mecole Hardman), 5 yards · pre-snap | +3% LAC +1.1 pts |
| Q4 15:00 | Defensive Offside on the Chargers (Jerry Tillery), 5 yards, wiping out the play · pre-snap | +12% KC +3.6 pts |
| Q4 12:48 | Offensive Holding on the Chargers (Alohi Gilman), 10 yards | +1% KC +0.9 pts |
| Q4 5:54 | Roughing the Passer on the Chiefs (Chris Jones), 15 yards | +12% LAC +1.5 pts |
| Q4 2:00 | False Start on the Chiefs, 5 yards · pre-snap | +9% LAC +0.5 pts |
| Q4 1:14 | Offensive Holding on the Chiefs, 10 yards, wiping out the play | +54% LAC +2.9 pts |
| Q4 0:25 | Offensive Holding on the Chiefs, 10 yards | +29% LAC +1.8 pts |
| QOT 6:12 | Defensive Offside on the Chargers (Melvin Ingram), 5 yards · pre-snap | +7% KC +0.6 pts |
| QOT 2:00 | False Start on the Chiefs, 5 yards · pre-snap | +11% KC +0.7 pts |
Chiefs penalties, every game · Chargers penalties, every game · All teams, 2020
When it happened
Chargers’ chance of winning
As low as 0% and as high as 91%. Numbers mark the biggest luck moments, listed below.
| # | When | What happened | Win probability for | Next drive |
|---|---|---|---|---|
| 1 | Q4 2:31 | M. Badgley made 23-yard field goalKicks · 99% expected for him | +16% LAC | LAC: Punt |
| 2 | Q4 1:19 | The Chiefs converted 3rd & 73rd & 4th downs · 37% expected | +12% KC | KC: Field goal |
| 3 | Q4 1:14 | Offensive Holding on the Chiefs, 10 yards, wiping out the playJudgment calls | +54% LAC | LAC: Punt |
| 4 | Q4 0:54 | The Chiefs converted 3rd & 203rd & 4th downs · 20% expected | +22% KC | KC: Field goal |
| 5 | Q4 0:25 | Offensive Holding on the Chiefs, 10 yardsJudgment calls | +29% LAC | LAC: Punt |
| 6 | QOT 4:15 | The Chiefs were stopped on 3rd & 43rd & 4th downs · 49% expected | +14% LAC | KC: Field goal |
| 7 | QOT 4:06 | The Chiefs converted 4th & 13rd & 4th downs · 76% expected | +21% KC | KC: Field goal |
| 8 | QOT 2:00 | The game turned hereH. Butker made 58-yard field goalKicks · 63% expected for him, 7 of 10 from 45+ beforeFalse Start on the Chiefs, 5 yardsPre-snap flags | +47% 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.
- Derwin James (LAC FS), out (IR) · 0.7 pts
- Drue Tranquill (LAC LB), out (IR) · 0.2 pts
- Charvarius Ward (KC CB), out · 0.6 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 90% · Chargers 10%
- Final margin
- Chiefs by 3
- Luck in points
- 4.9 for the Chargers
- Luck-adjusted margin
- Chiefs by 7.9
- Replay with same day's form
- Chiefs 40% · Chargers 60% 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 2 2020 games · 
Chiefs · 
Chargers
More from Week 2 2020
- Bengals at Browns CLE 35–30 · replay 97% for the winner
- Falcons at Cowboys DAL 40–39 · replay 56% for the winner
- Bills at Dolphins BUF 31–28 · replay 73% for the winner
- Panthers at Buccaneers TB 31–17 · replay 76% for the winner
- Broncos at Steelers PIT 26–21 · replay 64% for the winner
- Lions at Packers GB 42–21 · replay 75% for the winner
- Jaguars at Titans TEN 33–30 · replay 67% for the winner
- Rams at Eagles LA 37–19 · replay 90% for the winner
- Vikings at Colts IND 28–11 · replay 75% for the winner
- Giants at Bears CHI 17–13 · replay 22% for the winner
- 49ers at Jets SF 31–13 · replay 59% for the winner
- Washington at Cardinals ARI 30–15 · replay 76% for the winner
- Ravens at Texans BAL 33–16 · replay 89% for the winner
- Patriots at Seahawks SEA 35–30 · replay 56% for the winner
- Saints at Raiders LV 34–24 · replay 19% for the winner