luckadjusted

Week 18 2021 · January 9, 2022

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

Saints at Falcons, Week 18 2021: who deserved to win?

The Saints beat the Falcons 30–20 and were the better team on the day: replayed with the same form, they win 8 of 10. The Falcons had the bounces: kicks alone were worth 5.0 points to the Falcons.

Before kickoff the Saints were 63% favorites. The biggest swing (Q2, 9:08 left): the Saints converted 3rd & 9, worth 12 points of win probability to the Saints.

Final

New Orleans Saints 30
Atlanta Falcons 20

January 9, 2022 · Mercedes-Benz Stadium · Closing line: Saints −4.5

Luck index +23 Saints about even · −23 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. Saints win 8, Falcons win 2.

  1. 1 NO 42 ATL 16
  2. 2 NO 30 ATL 12
  3. 3 NO 20 ATL 6
  4. 4 NO 25 ATL 13
  5. 5 NO 26 ATL 17
  6. 6 NO 23 ATL 17
  7. 7 NO 13 ATL 10
  8. 8 NO 15 ATL 13
  9. 9 NO 20 ATL 24
  10. 10 NO 3 ATL 16

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

Saints win 77% of them, Falcons 23%, counting the 3% still level after regulation as half each. The line is what actually happened: Saints by 10.

Show as a table
Final margin in the replaysShare of replays
Saints by 17+28.9%
Saints by 9–1620.9%
Saints by 1–826.6%
Level after regulation3.1%
Falcons by 1–811.4%
Falcons by 9–166.9%
Falcons by 17+2.1%

Where the luck was

Take the luck out

The final margin was Saints by 10. Remove the luck, one kind at a time, and it becomes Saints by 14.0.

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.

  • Y. Koo, 48 yds made · 82% expected
  • B. Maher, 34 yds missed · 93% expected
  • Y. Koo, 54 yds made · 73% expected
  • B. Maher, 37 yds made · 90% expected
  • B. Maher, 27 yds made · 96% expected
  • B. Maher, 33 yds made · 94% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Falcons’ chance of winning

As low as 0% and as high as 59%. 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 Saints were.
#WhenWhat happenedWin probability forNext drive
1 Q1 4:00 The Falcons were stopped on 3rd & 93rd & 4th downs · 26% expected +5% NO ATL: Field goal
2 Q2 13:33 B. Maher missed 34-yard field goalKicks · 93% expected for him +7% ATL NO: Touchdown
3 Q2 12:33 The Falcons converted 3rd & 53rd & 4th downs · 37% expected +11% ATL ATL: Field goal
4 Q2 10:39 The Falcons were stopped on 3rd & 33rd & 4th downs · 48% expected +5% NO ATL: Field goal
5 Q2 9:08 The Saints converted 3rd & 93rd & 4th downs · 30% expected +12% NO NO: Touchdown
6 Q2 5:56 Defensive Pass Interference on the Falcons (Fabian Moreau), 11 yardsJudgment calls · 11 flags in 2032 snaps before, position avg 1 per 213 +6% NO NO: Touchdown
7 Q2 5:52 Unsportsmanlike Conduct on the Saints (Tre'Quan Smith), 15 yardsJudgment calls · 7 flags in 1678 snaps before, position avg 1 per 399 +5% ATL ATL: Turnover
8 Q2 1:08 B. Maher made 37-yard field goalKicks · 90% expected for him +6% ATL NO: 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.

  • Erik Harris (ATL FS), out (IR) · 0.3 pts
  • Jalen Mayfield (ATL G), out · 0.2 pts
  • Terron Armstead (NO T), out · 1.0 pts
  • P.J. Williams (NO CB), 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

Saints 99% · Falcons 1%

Final margin
Saints by 10
Luck in points
4.0 for the Falcons
Luck-adjusted margin
Saints by 14.0
Replay with same day's form
Saints 77% · Falcons 23% 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 18 2021 games · Saints · Falcons

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