luckadjusted

Week 8 2019 · October 27, 2019

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

Eagles at Bills, Week 8 2019: who deserved to win?

The Eagles beat the Bills 31–13, and it was no fluke: replayed with the way both teams actually played, the Eagles win 10 of 10. The Bills had the bounces: fumble bounces alone were worth 1.6 points to the Bills.

An off day for the Bills: their defense played far below its usual level. In a fresh game against the Eagles they would win 49% of the time; with this day’s form, 4%. The numbers

Before kickoff it was a pick’em. The biggest swing (Q2, 2:00 left): the Bills were stopped on 3rd & 2, worth 25 points of win probability to the Eagles.

Final

Philadelphia Eagles 31
Buffalo Bills 13

October 27, 2019 · New Era Field · Closing line: Bills −1

Luck index +4 Eagles about even · −4 Bills

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 10, Bills win 0.

  1. 1 PHI 37 BUF 0
  2. 2 PHI 30 BUF 0
  3. 3 PHI 34 BUF 10
  4. 4 PHI 23 BUF 3
  5. 5 PHI 26 BUF 9
  6. 6 PHI 25 BUF 10
  7. 7 PHI 18 BUF 6
  8. 8 PHI 31 BUF 22
  9. 9 PHI 19 BUF 14
  10. 10 PHI 12 BUF 10

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.

An off day for the Bills

Their defense played far below its usual level. In a fresh game against the Eagles they would win 49% of the time; with this day’s form, 4%.

44 points apart for the Bills: the gap is how differently this game went from what the two teams usually are.

UnitThis gameUsual levelBetter or worse than usual
Eagles offenseEPA per play gained +0.20 +0.12 better by 0.08
Eagles defenseEPA per play allowed −0.01 +0.14 better by 0.14
Bills offenseEPA per play gained −0.01 +0.07 worse by 0.08
Bills defenseEPA per play allowed +0.20 +0.05 worse by 0.14

EPA (expected points added) per play on competitive snaps, turnovers left out because they are valued as luck. Usual level: the team’s earlier games this season plus half of last season, pulled toward the league average. One team’s defense and the other team’s offense are the same snaps, so one game can’t fully say whose day it was; it shows how far this one was from both teams’ norms.

How 4,000 replays ended

Eagles win 96% of them, Bills 4%, counting the 1% still level after regulation as half each. The line is what actually happened: Eagles by 18.

Show as a table
Final margin in the replaysShare of replays
Eagles by 17+66.2%
Eagles by 9–1620.0%
Eagles by 1–89.1%
Level after regulation0.7%
Bills by 1–83.0%
Bills by 9–160.8%
Bills by 17+0.1%

Where the luck was

Take the luck out

The final margin was Eagles by 18. Remove the luck, one kind at a time, and it becomes Eagles by 13.5.

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.

  • J. Elliott, 37 yds made · 87% expected
  • S. Hauschka, 53 yds missed · 55% expected
  • Extra point missed · 93% expected
  • Extra point missed · 93% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Bills’ chance of winning

As low as 0% and as high as 72%. 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 Bills were ahead in it, below while the Eagles were.
#WhenWhat happenedWin probability forNext drive
1 Q2 14:54 The Bills converted 3rd & 143rd & 4th downs · 19% expected +11% BUF BUF: Touchdown
2 Q2 4:33 The Eagles converted 3rd & 83rd & 4th downs · 34% expected +7% PHI PHI: Punt
3 Q2 2:00 The Bills were stopped on 3rd & 23rd & 4th downs · 57% expectedThe Bills fumbled and the Eagles recoveredFumble bounces · loose balls are close to 50/50 +25% PHI BUF: Missed field goal
4 Q2 0:25 The Eagles’ two-point try was good3rd & 4th downs · 47% expectedUnnecessary Roughness on the Eagles (Zach Ertz), 15 yardsJudgment calls · 0 flags in 420 snaps before, position avg 1 per 253 +13% PHI PHI: Touchdown
5 Q2 0:02 S. Hauschka missed 53-yard field goalKicks · 55% expected for him, 3 of 5 from 45+ before +19% BUF BUF: Missed field goal
6 Q3 12:57 The Bills converted 3rd & 143rd & 4th downs · 19% expected +6% BUF BUF: Touchdown
7 Q3 11:13 The Bills converted 3rd & 83rd & 4th downs · 28% expected +10% BUF BUF: Touchdown
8 Q3 9:44 The Bills converted 3rd & 133rd & 4th downs · 20% expected +16% BUF BUF: 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.

  • Jason Croom (BUF TE), out (IR) · 0.3 pts
  • Jason Peters (PHI T), out · 0.6 pts
  • Nigel Bradham (PHI LB), out · 0.4 pts
  • Avonte Maddox (PHI CB), out · 0.4 pts
  • Hassan Ridgeway (PHI DT), 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 97% · Bills 3%

Final margin
Eagles by 18
Luck in points
4.5 for the Eagles
Luck-adjusted margin
Eagles by 13.5
Replay with same day's form
Eagles 96% · Bills 4% 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 2019 games · Eagles · Bills

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