luckadjusted

Week 4 2019 · September 29, 2019

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

Patriots at Bills, Week 4 2019: who deserved to win?

The Patriots beat the Bills 16–10, but the Bills played well enough to win it: they take 7 of 10 replays with the same day's form. Luck ran their way: judgment calls alone were worth 1.7 points to the Patriots.

The Patriots won on an off day: their offense played far below its usual level. In a fresh game against the Bills they would win 67% of the time; with this day’s form, 30%. The numbers

Before kickoff the Patriots were 70% favorites. The biggest swing (Q4, 1:34 left): the Bills were stopped on 3rd & 9, worth 15 points of win probability to the Patriots.

Final

New England Patriots 16
Buffalo Bills 10

September 29, 2019 · New Era Field · Closing line: Patriots −7

Luck index +70 Patriots very lucky · −70 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. Patriots win 3, Bills win 7.

  1. 1 NE 30 BUF 12
  2. 2 NE 33 BUF 24
  3. 3 NE 17 BUF 14
  4. 4 NE 17 BUF 19
  5. 5 NE 22 BUF 26
  6. 6 NE 34 BUF 41
  7. 7 NE 16 BUF 28
  8. 8 NE 26 BUF 41
  9. 9 NE 21 BUF 41
  10. 10 NE 6 BUF 34

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.

The Patriots won on an off day

Their offense played far below its usual level. In a fresh game against the Bills they would win 67% of the time; with this day’s form, 30%.

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

UnitThis gameUsual levelBetter or worse than usual
Patriots offenseEPA per play gained −0.19 +0.19 worse by 0.38
Patriots defenseEPA per play allowed −0.07 +0.05 better by 0.12
Bills offenseEPA per play gained −0.07 +0.08 worse by 0.15
Bills defenseEPA per play allowed −0.19 +0.07 better by 0.26

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

Patriots win 30% of them, Bills 70%, counting the 4% still level after regulation as half each. The line is what actually happened: Patriots by 6.

Show as a table
Final margin in the replaysShare of replays
Patriots by 17+4.7%
Patriots by 9–168.7%
Patriots by 1–813.8%
Level after regulation4.0%
Bills by 1–823.8%
Bills by 9–1619.7%
Bills by 17+25.3%

Where the luck was

Take the luck out

The final margin was Patriots by 6. Remove the luck, one kind at a time, and it becomes Patriots by 5.0.

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.

  • S. Hauschka, 46 yds made · 76% expected
  • S. Hauschka, 49 yds missed · 71% expected
  • S. Gostkowski, 23 yds made · 99% 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 65%. 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 Patriots were.
#WhenWhat happenedWin probability forNext drive
1 Q1 9:49 The Patriots converted 3rd & 93rd & 4th downs · 27% expected +10% NE NE: Touchdown
2 Q1 8:19 The Patriots converted 3rd & 53rd & 4th downs · 39% expected +10% NE NE: Touchdown
3 Q1 6:30 Blocked punt by the PatriotsSpecial teams +15% NE NE: Opp touchdown
4 Q3 10:40 The Bills converted 4th & 13rd & 4th downs · 63% expected +11% BUF BUF: Touchdown
5 Q3 8:14 Offensive Holding on the Bills, 9 yards, wiping out the playJudgment calls +9% NE NE: Punt
6 Q4 14:26 The Bills converted 3rd & 83rd & 4th downs · 29% expected +13% BUF BUF: Turnover on downs
7 Q4 10:50 The Bills were stopped on 4th & 33rd & 4th downs · 40% expected +12% NE BUF: Punt
8 Q4 1:34 The Bills were stopped on 3rd & 93rd & 4th downs · 26% expected +15% NE –

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.

  • Robert Foster (BUF WR), out · 0.5 pts
  • Taron Johnson (BUF CB), out · 0.4 pts
  • Devin Singletary (BUF RB), out · 0.2 pts
  • Dont'a Hightower (NE LB), out · 0.5 pts
  • David Andrews (NE C), out (IR) · 0.4 pts
  • Isaiah Wynn (NE T), out (IR) · 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

Patriots 73% · Bills 27%

Final margin
Patriots by 6
Luck in points
1.0 for the Patriots
Luck-adjusted margin
Patriots by 5.0
Replay with same day's form
Patriots 30% · Bills 70% 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 4 2019 games · Patriots · Bills

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