luckadjusted

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 it was a coin flip: replayed with the way both teams played, the Chiefs win 5 of 10. Luck ran their way: kicks alone were worth 1.7 points to the Chiefs.

The Chiefs won on an off day: their defense played far below its usual level. In a fresh game against the Panthers they would win 76% of the time; with this day’s form, 45%. The numbers

Before kickoff the Chiefs were 77% favorites. The biggest swing (Q4, 0:02 left): J. Slye missed 67-yard field goal, worth 31 points of win probability to the Chiefs.

Final

Carolina Panthers 31
Kansas City Chiefs 33

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

Luck index +55 Chiefs lucky · −55 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 42 KC 20
  2. 2 CAR 24 KC 10
  3. 3 CAR 37 KC 27
  4. 4 CAR 33 KC 27
  5. 5 CAR 16 KC 13
  6. 6 CAR 17 KC 20
  7. 7 CAR 28 KC 33
  8. 8 CAR 20 KC 28
  9. 9 CAR 13 KC 27
  10. 10 CAR 13 KC 34

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.

The Chiefs won on an off day

Their defense played far below its usual level. In a fresh game against the Panthers they would win 76% of the time; with this day’s form, 45%.

30 points apart for the Chiefs: the gap is how differently this game went from what the two teams usually are.

UnitThis gameUsual levelBetter or worse than usual
Panthers offenseEPA per play gained +0.32 +0.10 better by 0.22
Panthers defenseEPA per play allowed +0.27 +0.16 worse by 0.10
Chiefs offenseEPA per play gained +0.27 +0.23 better by 0.04
Chiefs defenseEPA per play allowed +0.32 +0.10 worse by 0.22

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

Panthers win 55% of them, Chiefs 45%, 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+10.9%
Panthers by 9–1614.6%
Panthers by 1–824.1%
Level after regulation5.9%
Chiefs by 1–822.0%
Chiefs by 9–1613.2%
Chiefs by 17+9.3%

Where the luck was

Take the luck out

The final margin was Chiefs by 2. Remove the luck, one kind at a time, and it becomes Chiefs by 5.9.

Each row takes one kind of luck out of the margin. Color shows which team it helped. Luck shares are the fitted ones (how much of each component 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 · 85% expected
  • H. Butker, 55 yds made · 56% expected
  • J. Slye, 47 yds made · 70% expected
  • H. Butker, 48 yds missed · 70% expected
  • J. Slye, 51 yds missed · 62% expected
  • J. Slye, 67 yds missed · 39% expected
  • Extra point missed · 93% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

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 · 33% expected +13% CAR CAR: Touchdown
2 Q2 11:06 H. Butker made 55-yard field goalKicks · 56% 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 · 39% expected +19% 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 · 21% expected +10% CAR CAR: Touchdown
8 Q4 0:02 J. Slye missed 67-yard field goalKicks · 39% expected for him, 17 of 25 from 45+ before +31% 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 27% · Chiefs 73%

Final margin
Chiefs by 2
Luck in points
3.8 for the Panthers
Luck-adjusted margin
Chiefs by 5.8
Replay with same day's form
Panthers 55% · Chiefs 45% 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 (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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