luckadjusted

Week 11 2023 · November 20, 2023

Eagles at Chiefs, Week 11 2023: who deserved to win?

The Eagles beat the Chiefs 21–17, but it was a coin flip: replayed with the way both teams played, the Eagles win 4 of 10. Luck ran their way: drops alone were worth 55 points of win probability to the Eagles.

Before kickoff the Chiefs were 57% favorites. The biggest swing (Q4, 1:35 left): the Chiefs were stopped on 4th & 25, worth 25 points of win probability to the Eagles.

Final

Philadelphia Eagles 21
Kansas City Chiefs 17

November 20, 2023 · GEHA Field at Arrowhead Stadium · Closing line: Chiefs −2.5

Luck index +58 Eagles lucky · −58 Chiefs

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. Eagles win 4, Chiefs win 6.

  1. 1 PHI 31 KC 10
  2. 2 PHI 47 KC 36
  3. 3 PHI 31 KC 25
  4. 4 PHI 27 KC 24
  5. 5 PHI 35 KC 37
  6. 6 PHI 7 KC 12
  7. 7 PHI 29 KC 37
  8. 8 PHI 10 KC 23
  9. 9 PHI 17 KC 36
  10. 10 PHI 9 KC 37

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

Eagles win 42% of them, Chiefs 58%, counting the 3% still level after regulation as half each. The line is what actually happened: Eagles by 4.

Show as a table
Final margin in the replaysShare of replays
Eagles by 17+8.3%
Eagles by 9–1612.0%
Eagles by 1–819.8%
Level after regulation2.7%
Chiefs by 1–826.4%
Chiefs by 9–1616.2%
Chiefs by 17+14.6%

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 +4.5 points to the Eagles: the final margin was Eagles by 4, without the luck Chiefs by 0.5. Luck shares are the fitted ones (how much of each kind is luck).

Penalties: Eagles 7 for 61 yards, Chiefs 7 for 55 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 7:56 Neutral Zone Infraction on the Eagles (Josh Sweat), 5 yards · pre-snap +1% KC +0.5 pts
Q1 2:53 Illegal Use of Hands on the Chiefs (L'Jarius Sneed), 5 yards +2% PHI +0.4 pts
Q2 3:08 Defensive Offside on the Eagles (Josh Sweat), 5 yards · pre-snap +8% KC +0.7 pts
Q2 0:44 False Start on the Chiefs, 5 yards · pre-snap +1% PHI +0.6 pts
Q2 0:19 Encroachment on the Eagles (Jalen Carter), 5 yards · pre-snap +2% KC +0.4 pts
Q3 12:27 Offensive Holding on the Chiefs, 10 yards +4% PHI +1.5 pts
Q3 7:38 False Start on the Chiefs, 5 yards · pre-snap +2% PHI +0.9 pts
Q3 3:34 Offensive Holding on the Chiefs (Travis Kelce), 10 yards, wiping out the play +5% PHI +1.0 pts
Q3 2:32 Defensive Pass Interference on the Eagles (Darius Slay), 16 yards +5% KC +2.0 pts
Q3 1:40 Illegal Contact on the Eagles (Eli Ricks), 5 yards +7% KC +1.6 pts
Q4 5:46 False Start on the Chiefs, 5 yards · pre-snap +4% PHI +0.7 pts
Q4 3:20 Offensive Holding on the Eagles, 10 yards +6% KC +0.9 pts
Q4 2:04 Roughing the Passer on the Eagles (Fletcher Cox), 15 yards +7% KC +2.2 pts
Q4 1:42 Intentional Grounding on the Chiefs (Patrick Mahomes), 15 yards +10% PHI +1.7 pts

Eagles penalties, every game · Chiefs penalties, every game · All teams, 2023

When it happened

Chiefs’ chance of winning

As low as 0% and as high as 89%. 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 Eagles were.
#WhenWhat happenedWin probability forNext drive
1 Q4 9:07 The Chiefs were stopped on 3rd & 43rd & 4th downs · 45% expectedJu.Watson dropped a catchable passDrops · 4 drops on 45 catchable balls before this +11% PHI KC: Punt
2 Q4 7:33 The Eagles converted 3rd & 53rd & 4th downs · 45% expected +10% PHI PHI: Touchdown
3 Q4 5:46 The Chiefs were stopped on 3rd & 123rd & 4th downs · 25% expectedFalse Start on the Chiefs, 5 yardsPre-snap flags +9% PHI KC: Punt
4 Q4 2:21 The Chiefs were stopped on 3rd & 23rd & 4th downs · 60% expectedT. Kelce dropped a catchable passDrops · 12 drops on 227 catchable balls before this +20% PHI KC: Turnover on downs
5 Q4 2:18 The Chiefs converted 4th & 23rd & 4th downs · 60% expected +9% KC KC: Turnover on downs
6 Q4 1:50 M. Valdes-Scantling dropped a catchable passDrops · 5 drops on 79 catchable balls before this +23% PHI KC: Turnover on downs
7 Q4 1:42 The Chiefs were stopped on 3rd & 103rd & 4th downs · 28% expectedIntentional Grounding on the Chiefs (Patrick Mahomes), 15 yardsJudgment calls · 6 flags in 5570 snaps before, position avg 1 per 643 +21% PHI KC: Turnover on downs
8 Q4 1:35 The Chiefs were stopped on 4th & 253rd & 4th downs · 16% expectedJu.Watson dropped a catchable passDrops · 5 drops on 47 catchable balls before this +25% PHI –

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 (IR) · 0.4 pts
  • Dallas Goedert (PHI TE), out · 1.1 pts
  • Justin Evans (PHI FS), out (IR) · 0.3 pts
  • Nakobe Dean (PHI LB), out (IR) · 0.1 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

Eagles 40% · Chiefs 60%

Final margin
Eagles by 4
Luck in points
4.5 for the Eagles
Luck-adjusted margin
Chiefs by 0.5
Replay with same day's form
Eagles 42% · Chiefs 58% 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 11 2023 games · Eagles · Chiefs

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