luckadjusted

AFC Championship 2023 · January 28, 2024

Chiefs at Ravens, AFC Championship 2023: who deserved to win?

The Chiefs beat the Ravens 17–10, but it was a coin flip: replayed with the way both teams played, the Chiefs win 5 of 10. Luck ran their way: fumble bounces alone were worth 4.7 points to the Chiefs.

Before kickoff the Ravens were 63% favorites. The biggest swing (Q2, 0:20 left): Offensive Holding on the Chiefs, 10 yards, wiping out the play, worth 16 points of win probability to the Ravens.

Final

Kansas City Chiefs 17
Baltimore Ravens 10

January 28, 2024 · M&T Bank Stadium · Closing line: Ravens −4.5

Luck index +51 Chiefs lucky · −51 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. Chiefs win 5, Ravens win 5.

  1. 1 KC 41 BAL 20
  2. 2 KC 28 BAL 14
  3. 3 KC 27 BAL 17
  4. 4 KC 13 BAL 7
  5. 5 KC 10 BAL 7
  6. 6 KC 24 BAL 26
  7. 7 KC 13 BAL 18
  8. 8 KC 24 BAL 34
  9. 9 KC 23 BAL 37
  10. 10 KC 7 BAL 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

Chiefs win 49% of them, Ravens 51%, 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
Chiefs by 17+11.3%
Chiefs by 9–1614.4%
Chiefs by 1–820.9%
Level after regulation5.8%
Ravens by 1–821.1%
Ravens by 9–1615.4%
Ravens by 17+11.1%

Where the luck was

Take the luck out

The final margin was Chiefs by 7. Remove the luck, one kind at a time, and it becomes Chiefs by 0.3.

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, 52 yds made · 72% expected
  • J. Tucker, 43 yds made · 84% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Ravens’ chance of winning

As low as 0% and as high as 55%. 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 Ravens were ahead in it, below while the Chiefs were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:40 The Ravens were stopped on 3rd & 73rd & 4th downs · 32% expectedN. Agholor dropped a catchable passDrops · 4 drops on 78 catchable balls before this +8% KC BAL: Punt
2 Q1 9:11 The Chiefs converted 4th & 23rd & 4th downs · 61% expected +10% KC KC: Touchdown
3 Q1 6:38 The Ravens converted 4th & 13rd & 4th downs · 72% expected +7% BAL BAL: Touchdown
4 Q1 0:18 The Chiefs converted 3rd & 43rd & 4th downs · 47% expected +7% KC KC: Touchdown
5 Q2 9:33 The Ravens fumbled and the Chiefs recoveredFumble bounces · loose balls are close to 50/50 +6% KC BAL: Punt
6 Q2 6:23 The Chiefs were stopped on 4th & 13rd & 4th downs · 75% expected +9% BAL KC: Punt
7 Q2 0:20 Offensive Holding on the Chiefs, 10 yards, wiping out the playJudgment calls +16% BAL BAL: End of half
8 Q4 15:00 The Ravens fumbled and the Chiefs recoveredFumble bounces · loose balls are close to 50/50 +9% KC BAL: Turnover

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.

  • Joe Thuney (KC G), out · 0.7 pts
  • Willie Gay Jr. (KC LB), out · 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

Chiefs 47% · Ravens 53%

Final margin
Chiefs by 7
Luck in points
6.7 for the Chiefs
Luck-adjusted margin
Chiefs by 0.3
Replay with same day's form
Chiefs 49% · Ravens 51% 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 Conference championships 2023 games · Chiefs · Ravens

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