luckadjusted

Week 4 2023 · October 1, 2023

Chiefs at Jets, Week 4 2023: who deserved to win?

The Chiefs beat the Jets 23–20, and it was no fluke: replayed with the way both teams actually played, the Chiefs win 8 of 10.

Before kickoff the Chiefs were 76% favorites. The biggest swing (Q4, 4:29 left): Defensive Holding on the Jets (Sauce Gardner), 5 yards, wiping out the play, worth 35 points of win probability to the Chiefs.

Final

Kansas City Chiefs 23
New York Jets 20

October 1, 2023 · MetLife Stadium · Closing line: Chiefs −9.5

Luck index +18 Chiefs about even · −18 Jets

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 8, Jets win 2.

  1. 1 KC 38 NYJ 7
  2. 2 KC 33 NYJ 10
  3. 3 KC 50 NYJ 33
  4. 4 KC 31 NYJ 17
  5. 5 KC 31 NYJ 20
  6. 6 KC 31 NYJ 23
  7. 7 KC 32 NYJ 27
  8. 8 KC 23 NYJ 21
  9. 9 KC 24 NYJ 27
  10. 10 KC 10 NYJ 23

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

Chiefs win 82% of them, Jets 18%, counting the 1% still level after regulation as half each. The line is what actually happened: Chiefs by 3.

Show as a table
Final margin in the replaysShare of replays
Chiefs by 17+34.9%
Chiefs by 9–1622.1%
Chiefs by 1–824.1%
Level after regulation1.0%
Jets by 1–811.1%
Jets by 9–165.2%
Jets by 17+1.6%

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 +8.6 points to the Chiefs: the final margin was Chiefs by 3, without the luck Jets by 5.6. 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, 37 yds made · 92% expected
  • G. Zuerlein, 31 yds made · 95% expected
  • H. Butker, 37 yds made · 92% expected
  • G. Zuerlein, 52 yds missed · 68% expected
  • H. Butker, 26 yds made · 99% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Chiefs 5 for 46 yards, Jets 7 for 42 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

WhenFlagWin probability for
Q1 15:00 Unnecessary Roughness on the Jets (Jermaine Johnson II), 15 yards +4% KC +2.1 pts
Q2 14:22 Illegal Block Above the Waist on the Chiefs (Joshua Williams), 4 yards +1% NYJ +0.4 pts
Q2 13:27 Face Mask on the Chiefs, 7 yards +1% KC +0.6 pts
Q2 9:42 Horse Collar Tackle on the Chiefs (Derrick Nnadi), 15 yards +4% NYJ +2.0 pts
Q2 9:42 False Start on the Jets, 5 yards · pre-snap +1% KC +0.6 pts
Q3 4:33 Ineligible Downfield Pass on the Jets, 5 yards, wiping out the play +8% KC +2.0 pts
Q4 14:23 Encroachment on the Jets (Quinnen Williams), 5 yards · pre-snap 0% KC +0.3 pts
Q4 6:42 Offensive Holding on the Chiefs, 10 yards, wiping out the play +12% NYJ +1.9 pts
Q4 6:21 Illegal Contact on the Jets (C.J. Mosley), 5 yards +3% KC +0.8 pts
Q4 4:38 Offensive Holding on the Chiefs, 10 yards, wiping out the play +17% NYJ +3.2 pts
Q4 4:29 Defensive Holding on the Jets (Sauce Gardner), 5 yards, wiping out the play +35% KC +7.1 pts
Q4 0:38 Unsportsmanlike Conduct on the Jets, 2 yards +2% KC +0.6 pts

Chiefs penalties, every game · Jets penalties, every game · All teams, 2023

When it happened

Jets’ chance of winning

As low as 0% and as high as 64%. 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 Jets were ahead in it, below while the Chiefs were.
#WhenWhat happenedWin probability forNext drive
1 Q1 8:41 The Chiefs converted 3rd & 13rd & 4th downs · 75% expected +12% KC KC: Touchdown
2 Q1 3:32 The Chiefs converted 3rd & 23rd & 4th downs · 61% expected +8% KC KC: Touchdown
3 Q3 10:44 The Jets converted 3rd & 83rd & 4th downs · 22% expected +16% NYJ NYJ: Touchdown
4 Q3 2:40 The Chiefs fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +11% KC KC: Field goal
5 Q4 7:30 The Jets fumbled and the Chiefs recoveredFumble bounces · loose balls are close to 50/50 +12% KC –
6 Q4 6:42 Offensive Holding on the Chiefs, 10 yards, wiping out the playJudgment calls +12% NYJ –
7 Q4 4:38 Offensive Holding on the Chiefs, 10 yards, wiping out the playJudgment calls +17% NYJ –
8 Q4 4:29 Defensive Holding on the Jets (Sauce Gardner), 5 yards, wiping out the playJudgment calls · 2 flags in 1434 snaps before, position avg 1 per 216 +35% KC KC: End of game

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.

  • Duane Brown (NYJ T), out (IR) · 1.0 pts
  • Nick Bolton (KC LB), out · 0.5 pts
  • Jaylen Watson (KC CB), out · 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

Chiefs 33% · Jets 67%

Final margin
Chiefs by 3
Luck in points
8.6 for the Chiefs
Luck-adjusted margin
Jets by 5.6
Replay with same day's form
Chiefs 82% · Jets 18% 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; injuries from snap counts and injury reports.

Methodology and validation · All Week 4 2023 games · Chiefs · Jets

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