luckadjusted

Week 8 2021 · November 1, 2021

No FTN charting for this game (drops and interception-worthy throws are not modelled).

Giants at Chiefs, Week 8 2021: who deserved to win?

The Chiefs beat the Giants 20–17, and it was no fluke: replayed with the way both teams actually played, the Chiefs win 8 of 10. The Giants had the bounces: judgment calls alone were worth 3.7 points to the Giants.

Before kickoff the Chiefs were 78% favorites. The biggest swing (Q4, 4:29 left): Defensive Offside on the Giants (Oshane Ximines), 5 yards, wiping out the play, worth 40 points of win probability to the Chiefs.

Final

New York Giants 17
Kansas City Chiefs 20

November 1, 2021 · GEHA Field at Arrowhead Stadium · Closing line: Chiefs −10.5

Luck index +19 Chiefs about even · −19 Giants

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. Giants win 2, Chiefs win 8.

  1. 1 NYG 25 KC 13
  2. 2 NYG 17 KC 14
  3. 3 NYG 23 KC 24
  4. 4 NYG 16 KC 20
  5. 5 NYG 19 KC 27
  6. 6 NYG 16 KC 27
  7. 7 NYG 20 KC 34
  8. 8 NYG 0 KC 17
  9. 9 NYG 13 KC 34
  10. 10 NYG 17 KC 45

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

Giants win 19% of them, Chiefs 81%, counting the 1% still level after regulation as half each. The line is what actually happened: Chiefs by 3.

Show as a table
Final margin in the replaysShare of replays
Giants by 17+2.1%
Giants by 9–164.7%
Giants by 1–812.3%
Level after regulation1.1%
Chiefs by 1–822.1%
Chiefs by 9–1621.2%
Chiefs by 17+36.4%

Where the luck was

Take the luck out

The final margin was Chiefs by 3. Remove the luck, one kind at a time, and it becomes Chiefs by 5.5.

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. Gano, 23 yds made · 100% expected
  • H. Butker, 36 yds made · 92% expected
  • H. Butker, 34 yds made · 94% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Chiefs’ chance of winning

As low as 39% and as high as 100%. 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 Giants were.
#WhenWhat happenedWin probability forNext drive
1 Q1 8:27 The Chiefs were stopped on 3rd & 53rd & 4th downs · 37% expected +14% NYG KC: Touchdown
2 Q1 1:56 The Giants converted 3rd & 113rd & 4th downs · 26% expected +10% NYG NYG: Touchdown
3 Q2 14:19 The Giants converted 4th & 13rd & 4th downs · 66% expected +13% NYG NYG: Touchdown
4 Q4 14:57 The Giants converted 3rd & 43rd & 4th downs · 37% expected +9% NYG NYG: Touchdown
5 Q4 11:58 Unnecessary Roughness on the Giants (Tae Crowder), 15 yardsJudgment calls · 1 flag in 896 snaps before, position avg 1 per 409 +12% KC KC: Field goal
6 Q4 11:04 The Chiefs converted 3rd & 113rd & 4th downs · 30% expected +10% KC KC: Field goal
7 Q4 7:28 The Giants converted 3rd & 13rd & 4th downs · 74% expectedTaunting on the Giants (Elijhaa Penny), 15 yardsJudgment calls · 3 flags in 840 snaps before, position avg 1 per 773 +9% KC NYG: Punt
8 Q4 4:29 Defensive Offside on the Giants (Oshane Ximines), 5 yards, wiping out the playPre-snap flags · 1 flag in 1137 snaps before, position avg 1 per 409 +40% KC KC: Field goal

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.

  • Mike Remmers (KC T), out · 0.6 pts
  • Anthony Hitchens (KC LB), out · 0.4 pts
  • Clyde Edwards-Helaire (KC RB), out (IR) · 0.2 pts
  • Andrew Thomas (NYG T), out (IR) · 0.9 pts
  • Kenny Golladay (NYG WR), out · 0.8 pts
  • Saquon Barkley (NYG RB), out · 0.6 pts
  • Blake Martinez (NYG LB), out (IR) · 0.4 pts
  • Nick Gates (NYG C), out (IR) · 0.4 pts
  • Jabrill Peppers (NYG SS), out (IR) · 0.3 pts
  • Lorenzo Carter (NYG LB), out · 0.3 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

Giants 11% · Chiefs 89%

Final margin
Chiefs by 3
Luck in points
2.5 for the Giants
Luck-adjusted margin
Chiefs by 5.5
Replay with same day's form
Giants 19% · Chiefs 81% 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 (not available for this game); injuries from snap counts and injury reports. No FTN charting for this game (drops and interception-worthy throws are not modelled).

Methodology and validation · All Week 8 2021 games · Giants · Chiefs

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