luckadjusted

Week 1 2021 · September 12, 2021

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

Eagles at Falcons, Week 1 2021: who deserved to win?

The Eagles beat the Falcons 32–6 and were the better team on the day: replayed with the same form, they win 7 of 10.

Before kickoff the Falcons were 60% favorites. The biggest swing (Q2, 12:55 left): the Eagles were stopped on 4th & 4, worth 12 points of win probability to the Falcons.

Final

Philadelphia Eagles 32
Atlanta Falcons 6

September 12, 2021 · Mercedes-Benz Stadium · Closing line: Falcons −3.5

Luck index +31 Eagles lucky · −31 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. Eagles win 7, Falcons win 3.

  1. 1 PHI 41 ATL 16
  2. 2 PHI 28 ATL 9
  3. 3 PHI 30 ATL 16
  4. 4 PHI 34 ATL 23
  5. 5 PHI 31 ATL 23
  6. 6 PHI 29 ATL 25
  7. 7 PHI 24 ATL 22
  8. 8 PHI 17 ATL 19
  9. 9 PHI 14 ATL 22
  10. 10 PHI 6 ATL 23

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 69% of them, Falcons 31%, counting the 4% still level after regulation as half each. The line is what actually happened: Eagles by 26.

Show as a table
Final margin in the replaysShare of replays
Eagles by 17+23.0%
Eagles by 9–1621.7%
Eagles by 1–823.2%
Level after regulation4.3%
Falcons by 1–815.2%
Falcons by 9–168.4%
Falcons by 17+4.2%

Where the luck was

Take the luck out

The final margin was Eagles by 26. Remove the luck, one kind at a time, and it becomes Eagles by 23.6.

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, 21 yds made · 100% expected
  • Y. Koo, 27 yds made · 98% expected
  • J. Elliott, 43 yds made · 82% 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 69%. 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 Eagles were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:08 The Falcons converted 3rd & 53rd & 4th downs · 40% expected +9% ATL ATL: Field goal
2 Q1 6:23 The Eagles converted 3rd & 43rd & 4th downs · 49% expected +8% PHI PHI: Touchdown
3 Q1 2:30 The Falcons converted 4th & 13rd & 4th downs · 73% expected +7% ATL ATL: Field goal
4 Q2 12:55 The Eagles were stopped on 4th & 43rd & 4th downs · 48% expected +12% ATL PHI: Punt
5 Q2 1:34 The Eagles converted 3rd & 13rd & 4th downs · 76% expected +7% PHI PHI: Touchdown
6 Q2 0:15 Ineligible Downfield Pass on the Eagles, 5 yards, wiping out the playJudgment calls +8% ATL ATL: End of half
7 Q3 7:03 The Eagles were stopped on 4th & 23rd & 4th downs · 63% expected +9% ATL PHI: Touchdown
8 Q3 5:28 Offensive Pass Interference on the Falcons (Calvin Ridley), 10 yards, wiping out the playJudgment calls · 6 flags in 1537 snaps before, position avg 1 per 399 +10% PHI PHI: 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.

  • Rodney McLeod (PHI S), out · 0.4 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 100% · Falcons 0%

Final margin
Eagles by 26
Luck in points
2.3 for the Eagles
Luck-adjusted margin
Eagles by 23.7
Replay with same day's form
Eagles 69% · Falcons 31% 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 1 2021 games · Eagles · Falcons

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