luckadjusted
NFL Week 9 · 2026

Week 4 2020 · October 5, 2020

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

Patriots at Chiefs, Week 4 2020: who deserved to win?

The Chiefs beat the Patriots 26–10, and the replays back it up: with the way both teams actually played, the Chiefs win 8 of 10.

Before kickoff the Chiefs were 70% favorites. The biggest swing (Q4, 14:21 left): Defensive Pass Interference on the Chiefs (Tyrann Mathieu), 16 yards, wiping out the play, worth 21 points of win probability to the Patriots.

Final

New England Patriots 10
Kansas City Chiefs 26

October 5, 2020 · Arrowhead Stadium · Closing line: Chiefs −7

Luck index +16 Chiefs about even · −16 Patriots

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. Patriots win 2, Chiefs win 8.

  1. 1 NE 22 KC 10
  2. 2 NE 10 KC 7
  3. 3 NE 22 KC 24
  4. 4 NE 19 KC 24
  5. 5 NE 20 KC 28
  6. 6 NE 20 KC 30
  7. 7 NE 13 KC 27
  8. 8 NE 21 KC 38
  9. 9 NE 13 KC 36
  10. 10 NE 6 KC 37

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

Patriots win 16% of them, Chiefs 84%, counting the 2% still level after regulation as half each. The line is what actually happened: Chiefs by 16.

Show as a table
Final margin in the replaysShare of replays
Patriots by 17+1.6%
Patriots by 9–163.5%
Patriots by 1–89.0%
Level after regulation2.0%
Chiefs by 1–821.4%
Chiefs by 9–1623.7%
Chiefs by 17+38.8%

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 +4.5 points to the Patriots: the final margin was Chiefs by 16, without the luck Chiefs by 20.5. 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, 23 yds made · 98% expected
  • H. Butker, 39 yds made · 88% expected
  • N. Folk, 43 yds made · 80% expected
  • Extra point missed · 94% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Patriots 4 for 43 yards, Chiefs 4 for 38 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 4:38 False Start on the Chiefs (Mecole Hardman), 2 yards · pre-snap +1% NE +0.6 pts
Q1 2:00 False Start on the Chiefs, 5 yards · pre-snap +1% NE +0.8 pts
Q2 5:44 Unsportsmanlike Conduct on the Chiefs, 15 yards +5% NE +1.4 pts
Q2 3:13 False Start on the Patriots, 5 yards · pre-snap +3% KC +1.0 pts
Q3 4:17 False Start on the Patriots (Jakob Johnson), 5 yards · pre-snap +4% KC +0.7 pts
Q4 14:21 Defensive Pass Interference on the Chiefs (Tyrann Mathieu), 16 yards, wiping out the play +21% NE +5.0 pts
Q4 12:17 Defensive Pass Interference on the Patriots (Kyle Dugger), 18 yards +7% KC +2.4 pts
Q4 12:11 Unnecessary Roughness on the Patriots (Deatrich Wise Jr.), 15 yards +7% KC +1.1 pts

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

When it happened

Chiefs’ chance of winning

As low as 45% 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 Patriots were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:00 The Chiefs converted 3rd & 53rd & 4th downs · 44% expected +7% KC KC: Field goal
2 Q2 2:46 The Patriots converted 3rd & 63rd & 4th downs · 36% expected +8% NE NE: End of half
3 Q3 4:01 The Patriots fumbled and the Chiefs recoveredFumble bounces · loose balls are close to 50/50 +10% KC NE: Touchdown
4 Q4 14:21 Defensive Pass Interference on the Chiefs (Tyrann Mathieu), 16 yards, wiping out the playJudgment calls · 3 flags in 1482 snaps before, position avg 1 per 510 +21% NE NE: Touchdown
5 Q4 12:17 Defensive Pass Interference on the Patriots (Kyle Dugger), 18 yardsJudgment calls · 0 flags in 107 snaps before, position avg 1 per 237 +7% KC KC: Touchdown
6 Q4 12:11 Unnecessary Roughness on the Patriots (Deatrich Wise Jr.), 15 yardsJudgment calls · 6 flags in 356 snaps before, position avg 1 per 390 +7% KC KC: Touchdown
7 Q4 10:57 The Chiefs converted 3rd & 93rd & 4th downs · 32% expected +7% KC KC: Touchdown
8 Q4 8:57 The Chiefs missed an extra pointKicks · extra points are made about 94% of the timeReturn touchdown by the ChiefsSpecial teams +7% KC KC: Opp touchdown

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.

  • Chris Jones (KC DT), out · 0.8 pts
  • L'Jarius Sneed (KC CB), out (IR) · 0.5 pts
  • Shaq Mason (NE OL), out · 0.6 pts
  • Shaq Mason (NE G), out · 0.5 pts
  • David Andrews (NE C), out (IR) · 0.4 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

Patriots 0% · Chiefs 100%

Final margin
Chiefs by 16
Luck in points
4.5 for the Patriots
Luck-adjusted margin
Chiefs by 20.5
Replay with same day's form
Patriots 16% · Chiefs 84% 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 4 2020 games · Patriots · Chiefs

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