luckadjusted

Week 5 2023 · October 8, 2023

Chiefs at Vikings, Week 5 2023: who deserved to win?

The Chiefs beat the Vikings 27–20 and were the better team on the day: replayed with the same form, they win 8 of 10. The Vikings had the bounces: judgment calls alone were worth 4.5 points to the Vikings.

Before kickoff the Chiefs were 60% favorites. The biggest swing (Q4, 4:54 left): the Vikings were stopped on 4th & 12, worth 13 points of win probability to the Chiefs.

Final

Kansas City Chiefs 27
Minnesota Vikings 20

October 8, 2023 · U.S. Bank Stadium · Closing line: Chiefs −3.5

Luck index +22 Chiefs about even · −22 Vikings

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, Vikings win 2.

  1. 1 KC 37 MIN 13
  2. 2 KC 28 MIN 10
  3. 3 KC 34 MIN 21
  4. 4 KC 34 MIN 24
  5. 5 KC 17 MIN 10
  6. 6 KC 23 MIN 17
  7. 7 KC 17 MIN 14
  8. 8 KC 22 MIN 20
  9. 9 KC 21 MIN 24
  10. 10 KC 13 MIN 24

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 78% of them, Vikings 22%, counting the 5% 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+19.7%
Chiefs by 9–1623.4%
Chiefs by 1–831.7%
Level after regulation4.9%
Vikings by 1–813.7%
Vikings by 9–165.2%
Vikings by 17+1.4%

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 6.9.

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.

  • G. Joseph, 40 yds made · 89% expected
  • H. Butker, 38 yds made · 92% expected
  • G. Joseph, 29 yds made · 97% expected
  • H. Butker, 40 yds made · 90% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Vikings’ chance of winning

As low as 0% and as high as 61%. 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 Vikings were ahead in it, below while the Chiefs were.
#WhenWhat happenedWin probability forNext drive
1 Q1 6:29 The Vikings converted 4th & 53rd & 4th downs · 39% expected +9% MIN MIN: Field goal
2 Q1 4:10 The Vikings were stopped on 3rd & 73rd & 4th downs · 33% expectedT. Hockenson dropped a catchable passDrops · 2 drops on 140 catchable balls before this +8% KC MIN: Field goal
3 Q2 5:06 The Vikings converted 4th & 23rd & 4th downs · 58% expected +11% MIN MIN: Touchdown
4 Q3 13:45 The Chiefs converted 3rd & 183rd & 4th downs · 20% expected +12% KC KC: Touchdown
5 Q3 10:13 The Chiefs converted 3rd & 83rd & 4th downs · 27% expected +13% KC KC: Touchdown
6 Q3 8:29 The Chiefs converted 3rd & 73rd & 4th downs · 36% expected +8% KC KC: Touchdown
7 Q3 6:05 Defensive Pass Interference on the Vikings (Harrison Smith), 31 yardsJudgment calls · 11 flags in 4645 snaps before, position avg 1 per 462 +10% KC KC: Touchdown
8 Q4 4:54 The Vikings were stopped on 4th & 123rd & 4th downs · 23% expectedDelay of Game on the Vikings, 5 yardsPre-snap flags +13% KC MIN: 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.

  • Nick Bolton (KC LB), out · 0.5 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 79% · Vikings 21%

Final margin
Chiefs by 7
Luck in points
0.1 for the Chiefs
Luck-adjusted margin
Chiefs by 6.9
Replay with same day's form
Chiefs 78% · Vikings 22% 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 5 2023 games · Chiefs · Vikings

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