luckadjusted

Week 3 2024 · September 22, 2024

Chiefs at Falcons, Week 3 2024: who deserved to win?

The Chiefs beat the Falcons 22–17, and it was no fluke: replayed with the way both teams actually played, the Chiefs win 8 of 10. The Falcons had the bounces: judgment calls alone were worth 17 points of win probability to the Falcons.

Before kickoff the Chiefs were 59% favorites. The biggest swing (Q4, 0:56 left): the Falcons were stopped on 4th & 1, worth 35 points of win probability to the Chiefs.

Final

Kansas City Chiefs 22
Atlanta Falcons 17

September 22, 2024 · Mercedes-Benz Stadium · Closing line: Chiefs −3

Luck index +19 Chiefs about even · −19 Falcons

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, Falcons win 2.

  1. 1 KC 33 ATL 6
  2. 2 KC 34 ATL 14
  3. 3 KC 30 ATL 13
  4. 4 KC 28 ATL 15
  5. 5 KC 28 ATL 18
  6. 6 KC 26 ATL 19
  7. 7 KC 27 ATL 24
  8. 8 KC 26 ATL 24
  9. 9 KC 20 ATL 23
  10. 10 KC 16 ATL 27

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 81% of them, Falcons 19%, counting the 2% still level after regulation as half each. The line is what actually happened: Chiefs by 5.

Show as a table
Final margin in the replaysShare of replays
Chiefs by 17+30.0%
Chiefs by 9–1621.9%
Chiefs by 1–828.2%
Level after regulation2.2%
Falcons by 1–810.4%
Falcons by 9–165.2%
Falcons by 17+2.1%

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 +5.0 points to the Falcons: the final margin was Chiefs by 5, without the luck Chiefs by 10. 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, 53 yds made · 75% expected
  • H. Butker, 44 yds made · 85% expected
  • H. Butker, 21 yds made · 100% expected
  • Y. Koo, 54 yds made · 72% expected
  • Extra point missed · 93% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Chiefs 6 for 61 yards, Falcons 6 for 44 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 11:07 Offensive Holding on the Chiefs (Leo Chenal), 10 yards +2% ATL +1.4 pts
Q1 5:10 Defensive Too Many Men on Field on the Falcons, 6 yards · pre-snap +2% KC +0.6 pts
Q2 8:51 Roughing the Passer on the Falcons (Lorenzo Carter), 8 yards +3% KC +0.8 pts
Q2 7:56 Roughing the Passer on the Chiefs (Chris Jones), 15 yards +5% ATL +1.2 pts
Q2 2:00 Illegal Kick/Kicking Loose Ball on the Falcons (Bijan Robinson), 10 yards +3% KC +0.7 pts
Q2 0:59 False Start on the Falcons, 5 yards · pre-snap +2% KC +0.2 pts
Q3 1:16 Illegal Block Above the Waist on the Falcons (Ross Dwelley), 10 yards +1% KC +0.8 pts
Q4 11:22 Illegal Use of Hands on the Falcons, 5 yards +3% KC +0.8 pts
Q4 6:44 Neutral Zone Infraction on the Chiefs (Justin Reid), 5 yards · pre-snap +7% ATL +0.7 pts
Q4 2:26 Illegal Use of Hands on the Chiefs (Chamarri Conner), 5 yards +1% ATL +0.3 pts
Q4 2:01 Defensive Pass Interference on the Chiefs (Trent McDuffie), 11 yards +2% ATL +0.8 pts
Q4 1:51 Horse Collar Tackle on the Chiefs (Jaylen Watson), 15 yards +15% ATL +1.7 pts

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

When it happened

Falcons’ chance of winning

As low as 0% and as high as 75%. 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 Falcons were ahead in it, below while the Chiefs were.
#WhenWhat happenedWin probability forNext drive
1 Q2 8:51 The Chiefs converted 3rd & 33rd & 4th downs · 53% expectedRoughing the Passer on the Falcons (Lorenzo Carter), 8 yardsJudgment calls · 6 flags in 3373 snaps before, position avg 1 per 445 +13% KC KC: Touchdown
2 Q3 1:21 The Chiefs converted 3rd & 73rd & 4th downs · 35% expected +13% KC KC: Touchdown
3 Q4 11:36 The Chiefs were stopped on 3rd & 23rd & 4th downs · 61% expectedT. Kelce dropped a catchable passDrops · 20 drops on 308 catchable balls before this +10% ATL KC: Punt
4 Q4 6:08 The Falcons converted 4th & 23rd & 4th downs · 60% expected +15% ATL ATL: Turnover on downs
5 Q4 4:08 The Falcons were stopped on 4th & 53rd & 4th downs · 32% expected +19% KC ATL: Turnover on downs
6 Q4 1:51 Horse Collar Tackle on the Chiefs (Jaylen Watson), 15 yardsJudgment calls · 5 flags in 1803 snaps before, position avg 1 per 215 +15% ATL ATL: Turnover on downs
7 Q4 1:03 The Falcons were stopped on 3rd & 13rd & 4th downs · 73% expected +10% KC ATL: Turnover on downs
8 Q4 0:56 The Falcons were stopped on 4th & 13rd & 4th downs · 72% expected +35% 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.

  • DeMarcco Hellams (ATL SS), out (IR) · 0.2 pts
  • Isiah Pacheco (KC RB), out (IR) · 0.4 pts
  • 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

Chiefs 95% · Falcons 5%

Final margin
Chiefs by 5
Luck in points
5.0 for the Falcons
Luck-adjusted margin
Chiefs by 10.0
Replay with same day's form
Chiefs 81% · Falcons 19% 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 3 2024 games · Chiefs · Falcons

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