luckadjusted
NFL Week 9 · 2026

Week 9 2020 · November 8, 2020

No FTN charting for this game (drops and interception-worthy throws are not modelled).

Panthers at Chiefs, Week 9 2020: who deserved to win?

The Chiefs beat the Panthers 33–31, but the replays call it close to a coin flip: with the way both teams played, the Chiefs win 5 of 10. Luck ran their way: kicks alone were worth 19 points of win probability to the Chiefs.

Before kickoff the Chiefs were 77% favorites. The biggest swing (Q2, 0:11 left): Offensive Pass Interference on the Chiefs (Travis Kelce), 10 yards, worth 13 points of win probability to the Panthers.

Final

Carolina Panthers 31
Kansas City Chiefs 33

November 8, 2020 · Arrowhead Stadium · Closing line: Chiefs −10

Luck index +53 Chiefs lucky · −53 Panthers

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. Panthers win 5, Chiefs win 5.

  1. 1 CAR 45 KC 24
  2. 2 CAR 26 KC 13
  3. 3 CAR 29 KC 21
  4. 4 CAR 21 KC 17
  5. 5 CAR 31 KC 29
  6. 6 CAR 27 KC 30
  7. 7 CAR 31 KC 37
  8. 8 CAR 10 KC 19
  9. 9 CAR 12 KC 26
  10. 10 CAR 7 KC 30

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

Panthers win 53% of them, Chiefs 47%, counting the 6% still level after regulation as half each. The line is what actually happened: Chiefs by 2.

Show as a table
Final margin in the replaysShare of replays
Panthers by 17+10.8%
Panthers by 9–1614.8%
Panthers by 1–822.9%
Level after regulation5.9%
Chiefs by 1–822.3%
Chiefs by 9–1613.4%
Chiefs by 17+10.1%

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.

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 +5.8 points to the Panthers: the final margin was Chiefs by 2, without the luck Chiefs by 7.8. 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.

  • H. Butker, 39 yds made · 86% expected
  • H. Butker, 55 yds made · 58% expected
  • J. Slye, 47 yds made · 70% expected
  • H. Butker, 48 yds missed · 69% expected
  • J. Slye, 51 yds missed · 61% expected
  • J. Slye, 67 yds missed · 15% expected
  • Extra point missed · 94% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Panthers 12 for 82 yards, Chiefs 8 for 75 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

WhenFlagWin probability for
Q1 13:47 Illegal Use of Hands on the Chiefs (Chris Jones), 5 yards 0% CAR +0.3 pts
Q1 9:02 Defensive Holding on the Chiefs, 5 yards +1% CAR +0.7 pts
Q1 8:08 False Start on the Panthers (Robbie Chosen), 5 yards · pre-snap +4% KC +0.6 pts
Q1 3:37 Unnecessary Roughness on the Panthers (Rasul Douglas), 15 yards +6% KC +1.5 pts
Q2 10:20 Illegal Formation on the Panthers (Curtis Samuel), 5 yards · pre-snap +2% KC +0.6 pts
Q2 8:48 Offensive Pass Interference on the Panthers (Curtis Samuel), 10 yards, wiping out the play +3% KC +1.7 pts
Q2 1:19 Roughing the Passer on the Chiefs (Chris Jones), 15 yards +7% CAR +0.9 pts
Q2 0:11 Offensive Pass Interference on the Chiefs (Travis Kelce), 10 yards +13% CAR +0.5 pts
Q2 0:08 Defensive Offside on the Panthers (Derrick Brown), 5 yards, wiping out the play · pre-snap +10% CAR +2.5 pts
Q3 15:00 Defensive Holding on the Panthers (Derrick Brown), 5 yards +3% KC +0.7 pts
Q3 3:20 Face Mask on the Chiefs, 15 yards +8% CAR +1.8 pts
Q3 2:58 Offensive Holding on the Panthers, 10 yards +9% KC +1.3 pts
Q4 15:00 Defensive Offside on the Panthers (Brian Burns), 5 yards · pre-snap +1% KC +0.5 pts
Q4 14:23 Unnecessary Roughness on the Chiefs, 15 yards +2% CAR +1.4 pts
Q4 14:23 Offside on Free Kick on the Chiefs, 5 yards · pre-snap +2% CAR +0.5 pts
Q4 10:22 Illegal Touch Kick on the Panthers, 5 yards +1% KC +0.5 pts
Q4 8:09 Defensive Offside on the Panthers (Donte Jackson), 5 yards · pre-snap +3% KC +0.8 pts
Q4 8:03 Defensive Holding on the Panthers (Jermaine Carter Jr.), 2 yards +1% KC +0.6 pts
Q4 1:10 Defensive Holding on the Chiefs (Tyrann Mathieu), 5 yards +3% KC 0.0 pts
Q4 1:05 Illegal Use of Hands on the Panthers, 10 yards +8% KC +0.4 pts

Panthers penalties, every game · Chiefs penalties, every game · All teams, 2020

When it happened

Chiefs’ chance of winning

As low as 22% 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 Chiefs were ahead in it, below while the Panthers were.
#WhenWhat happenedWin probability forNext drive
1 Q2 14:54 The Panthers converted 4th & 73rd & 4th downs · 36% expected +11% CAR CAR: Touchdown
2 Q2 11:06 H. Butker made a 55-yard field goalKicks · 58% expected for him, 8 of 11 from 45+ before +10% KC KC: Touchdown
3 Q2 0:11 Offensive Pass Interference on the Chiefs (Travis Kelce), 10 yardsJudgment calls · 9 flags in 1611 snaps before, position avg 1 per 276 +13% CAR CAR: Missed field goal
4 Q2 0:08 Defensive Offside on the Panthers (Derrick Brown), 5 yards, wiping out the playPre-snap flags · 5 flags in 388 snaps before, position avg 1 per 262 +10% CAR KC: Turnover
5 Q3 6:09 The Chiefs converted 3rd & 73rd & 4th downs · 41% expected +10% KC KC: Touchdown
6 Q3 2:58 Offensive Holding on the Panthers, 10 yardsJudgment calls +9% KC KC: Touchdown
7 Q4 13:09 The Panthers converted 4th & 143rd & 4th downs · 23% expected +10% CAR CAR: Touchdown
8 Q4 0:02 J. Slye missed a 67-yard field goalKicks · 15% expected for him, 17 of 25 from 45+ before +12% 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.

  • Mitchell Schwartz (KC T), out · 1.5 pts
  • Sammy Watkins (KC WR), out · 0.8 pts
  • Kelechi Osemele (KC G), out (IR) · 0.5 pts
  • L'Jarius Sneed (KC CB), out (IR) · 0.5 pts
  • Russell Okung (CAR T), out · 0.9 pts
  • Jeremy Chinn (CAR S), out · 0.8 pts
  • Kawann Short (CAR DT), out (IR) · 0.4 pts
  • Juston Burris (CAR S), 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

Panthers 13% · Chiefs 87%

Final margin
Chiefs by 2
Luck in points
5.8 for the Panthers
Luck-adjusted margin
Chiefs by 7.8
Replay with same day's form
Panthers 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

None by default: our tests measured no carryover after a lucky break. Slide it up to count a break for more than its own swing. 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 (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 9 2020 games · Panthers · Chiefs

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