luckadjusted

Week 7 2022 · October 23, 2022

Chiefs at 49ers, Week 7 2022: who deserved to win?

The Chiefs beat the 49ers 44–23, and it was no fluke: replayed with the way both teams actually played, the Chiefs win 9 of 10. The 49ers had the bounces: kicks alone were worth 6.2 points to the 49ers.

An off day for the 49ers: their defense played far below its usual level. In a fresh game against the Chiefs they would win 42% of the time; with this day’s form, 7%. The numbers

Before kickoff it was a pick’em. The biggest swing (Q2, 1:34 left): the 49ers were stopped on 3rd & 3, worth 30 points of win probability to the Chiefs.

Final

Kansas City Chiefs 44
San Francisco 49ers 23

October 23, 2022 · Levi's Stadium · Closing line: Chiefs −1

Luck index +7 Chiefs about even · −7 49ers

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 9, 49ers win 1.

  1. 1 KC 42 SF 6
  2. 2 KC 44 SF 17
  3. 3 KC 34 SF 12
  4. 4 KC 40 SF 21
  5. 5 KC 35 SF 20
  6. 6 KC 37 SF 24
  7. 7 KC 21 SF 13
  8. 8 KC 23 SF 17
  9. 9 KC 30 SF 27
  10. 10 KC 37 SF 42

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.

An off day for the 49ers

Their defense played far below its usual level. In a fresh game against the Chiefs they would win 42% of the time; with this day’s form, 7%.

35 points apart for the 49ers: the gap is how differently this game went from what the two teams usually are.

UnitThis gameUsual levelBetter or worse than usual
Chiefs offenseEPA per play gained +0.70 +0.21 better by 0.49
Chiefs defenseEPA per play allowed +0.26 +0.12 worse by 0.14
49ers offenseEPA per play gained +0.26 +0.15 better by 0.11
49ers defenseEPA per play allowed +0.70 +0.04 worse by 0.66

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

Chiefs win 93% of them, 49ers 7%, counting the 1% still level after regulation as half each. The line is what actually happened: Chiefs by 21.

Show as a table
Final margin in the replaysShare of replays
Chiefs by 17+58.7%
Chiefs by 9–1619.7%
Chiefs by 1–814.8%
Level after regulation0.5%
49ers by 1–84.3%
49ers by 9–161.6%
49ers by 17+0.4%

Where the luck was

Take the luck out

The final margin was Chiefs by 21. Remove the luck, one kind at a time, and it becomes Chiefs by 23.2.

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.

  • R. Gould, 30 yds made · 95% expected
  • R. Gould, 50 yds made · 69% expected
  • H. Butker, 39 yds missed · 89% expected
  • R. Gould, 49 yds made · 71% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

49ers’ chance of winning

As low as 0% and as high as 79%. 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 49ers were ahead in it, below while the Chiefs were.
#WhenWhat happenedWin probability forNext drive
1 Q1 8:50 The Chiefs were stopped on 3rd & 73rd & 4th downs · 41% expectedThe Chiefs threw an interception-worthy pass, and it was pickedInterceptions · 45% expected to stay out of the defense's hands +12% SF KC: Touchdown
2 Q2 1:34 The 49ers were stopped on 3rd & 33rd & 4th downs · 42% expectedThe 49ers threw an interception-worthy pass, and it was pickedInterceptions · 46% expected to stay out of the defense's hands +30% KC SF: End of half
3 Q2 0:19 The Chiefs fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50The Chiefs got away with an interception-worthy throwInterceptions · 46% expected to stay out of the defense's hands +11% KC KC: Missed field goal
4 Q2 0:16 Low Block on the Chiefs (Jerick McKinnon), 15 yards, wiping out the playJudgment calls · 1 flag in 1100 snaps before, position avg 1 per 821 +14% SF SF: End of half
5 Q2 0:11 H. Butker missed 39-yard field goalKicks · 89% expected for him +18% SF KC: Touchdown
6 Q3 4:22 The Chiefs converted 3rd & 203rd & 4th downs · 23% expected +10% KC KC: Touchdown
7 Q4 14:20 The 49ers converted 3rd & 103rd & 4th downs · 27% expected +11% SF SF: Touchdown
8 Q4 12:54 The Chiefs converted 3rd & 113rd & 4th downs · 32% expected +14% KC KC: 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.

  • Emmanuel Moseley (SF CB), out (IR) · 0.6 pts
  • Arik Armstead (SF DE), out · 0.5 pts
  • Javon Kinlaw (SF DT), out (IR) · 0.3 pts
  • Rashad Fenton (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 100% · 49ers 0%

Final margin
Chiefs by 21
Luck in points
2.2 for the 49ers
Luck-adjusted margin
Chiefs by 23.2
Replay with same day's form
Chiefs 93% · 49ers 7% 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 7 2022 games · Chiefs · 49ers

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