luckadjusted

Week 1 2024 · September 5, 2024

Ravens at Chiefs, Week 1 2024: who deserved to win?

The Chiefs beat the Ravens 27–20, but it was a coin flip: replayed with the way both teams played, the Chiefs win 5 of 10. Luck ran their way: judgment calls alone were worth 18 points of win probability to the Chiefs.

Before kickoff the Chiefs were 59% favorites. The biggest swing (Q4, 0:05 left): the Ravens were stopped on 3rd & 10, worth 16 points of win probability to the Chiefs.

Final

Baltimore Ravens 20
Kansas City Chiefs 27

September 5, 2024 · GEHA Field at Arrowhead Stadium · Closing line: Chiefs −3

Luck index +52 Chiefs lucky · −52 Ravens

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. Ravens win 5, Chiefs win 5.

  1. 1 BAL 45 KC 22
  2. 2 BAL 30 KC 16
  3. 3 BAL 33 KC 24
  4. 4 BAL 26 KC 21
  5. 5 BAL 16 KC 14
  6. 6 BAL 16 KC 19
  7. 7 BAL 30 KC 36
  8. 8 BAL 24 KC 33
  9. 9 BAL 3 KC 17
  10. 10 BAL 9 KC 32

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

Ravens win 52% of them, Chiefs 48%, counting the 6% still level after regulation as half each. The line is what actually happened: Chiefs by 7.

Show as a table
Final margin in the replaysShare of replays
Ravens by 17+11.3%
Ravens by 9–1614.5%
Ravens by 1–822.3%
Level after regulation5.9%
Chiefs by 1–820.3%
Chiefs by 9–1614.7%
Chiefs by 17+11.2%

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 +4.3 points to the Chiefs: the final margin was Chiefs by 7, without the luck Chiefs by 2.7. 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, 32 yds made · 96% expected
  • H. Butker, 31 yds made · 97% expected
  • J. Tucker, 53 yds missed · 70% expected
  • J. Tucker, 25 yds made · 100% expected
  • J. Tucker, 32 yds made · 96% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Ravens 7 for 64 yards, Chiefs 6 for 45 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 14:19 Illegal Formation on the Ravens, 5 yards · pre-snap +2% KC +0.9 pts
Q1 6:23 Horse Collar Tackle on the Ravens (Roquan Smith), 15 yards +4% KC +1.9 pts
Q2 14:44 Offensive Holding on the Chiefs (Travis Kelce), 10 yards +2% BAL +1.0 pts
Q2 11:36 Offensive Pass Interference on the Ravens (Rashod Bateman), 10 yards +6% KC +1.9 pts
Q2 8:20 False Start on the Chiefs, 5 yards · pre-snap +2% BAL +0.7 pts
Q2 5:44 Defensive Pass Interference on the Chiefs (Drue Tranquill), 5 yards +1% BAL +0.4 pts
Q2 3:46 Delay of Game on the Ravens, 5 yards · pre-snap +4% KC +0.7 pts
Q2 2:41 Illegal Formation on the Ravens, 5 yards, wiping out the play · pre-snap +4% KC +1.2 pts
Q3 15:00 Offensive Holding on the Chiefs (Jack Cochrane), 10 yards +1% BAL +0.9 pts
Q3 12:45 Offensive Holding on the Chiefs, 10 yards, wiping out the play +7% BAL +2.0 pts
Q3 12:23 Roughing the Passer on the Ravens (Nnamdi Madubuike), 14 yards +6% KC +1.5 pts
Q3 0:46 Offensive Holding on the Ravens, 10 yards, wiping out the play +11% KC +3.4 pts
Q4 4:14 False Start on the Chiefs, 5 yards · pre-snap +1% BAL +0.3 pts

Ravens penalties, every game · Chiefs penalties, every game · All teams, 2024

When it happened

Chiefs’ chance of winning

As low as 38% 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 Ravens were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:20 The Ravens converted 3rd & 113rd & 4th downs · 26% expected +8% BAL BAL: Touchdown
2 Q1 11:49 The Ravens converted 3rd & 93rd & 4th downs · 30% expected +10% BAL BAL: Touchdown
3 Q2 14:53 The Ravens fumbled and the Chiefs recoveredFumble bounces · loose balls are close to 50/50 +7% KC BAL: Turnover on downs
4 Q2 9:45 The Ravens were stopped on 4th & 33rd & 4th downs · 52% expected +8% KC BAL: Missed field goal
5 Q2 8:05 The Chiefs converted 3rd & 123rd & 4th downs · 26% expected +7% KC KC: Field goal
6 Q3 0:46 Offensive Holding on the Ravens, 10 yards, wiping out the playJudgment calls +11% KC KC: Touchdown
7 Q4 2:36 The Chiefs were stopped on 3rd & 103rd & 4th downs · 30% expectedThe Chiefs got away with an interception-worthy throwInterceptions · 50% expected to stay out of the defense's hands +12% KC KC: Punt
8 Q4 0:05 The Ravens were stopped on 3rd & 103rd & 4th downs · 22% expected +16% 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.

  • Charles Omenihu (KC DE), out (IR) · 0.2 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

Ravens 37% · Chiefs 63%

Final margin
Chiefs by 7
Luck in points
4.3 for the Chiefs
Luck-adjusted margin
Chiefs by 2.7
Replay with same day's form
Ravens 52% · Chiefs 48% 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 1 2024 games · Ravens · Chiefs

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