luckadjusted

Week 4 2021 · October 3, 2021

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

Texans at Bills, Week 4 2021: who deserved to win?

The Bills beat the Texans 40–0, and it was no fluke: replayed with the way both teams actually played, the Bills win 10 of 10.

Before kickoff the Bills were 92% favorites. The biggest swing (Q1, 10:10 left): the Texans were stopped on 4th & 3, worth 13 points of win probability to the Bills.

Final

Houston Texans 0
Buffalo Bills 40

October 3, 2021 · New Era Field · Closing line: Bills −19

Luck index +2 Bills about even · −2 Texans

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. Texans win 0, Bills win 10.

  1. 1 HOU 20 BUF 24
  2. 2 HOU 27 BUF 34
  3. 3 HOU 31 BUF 41
  4. 4 HOU 17 BUF 30
  5. 5 HOU 16 BUF 32
  6. 6 HOU 13 BUF 33
  7. 7 HOU 13 BUF 36
  8. 8 HOU 23 BUF 50
  9. 9 HOU 20 BUF 51
  10. 10 HOU 3 BUF 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

Texans win 2% of them, Bills 98%. The line is what actually happened: Bills by 40.

Show as a table
Final margin in the replaysShare of replays
Texans by 17+0.1%
Texans by 9–160.3%
Texans by 1–81.8%
Level after regulation0.4%
Bills by 1–85.8%
Bills by 9–1612.8%
Bills by 17+78.8%

Where the luck was

Take the luck out

The final margin was Bills by 40. Remove the luck, one kind at a time, and it becomes Bills by 21.4.

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.

  • T. Bass, 33 yds made · 93% expected
  • T. Bass, 26 yds made · 97% expected
  • T. Bass, 21 yds made · 99% expected
  • T. Bass, 28 yds made · 96% 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 43% 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 Bills were ahead in it, below while the Texans were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:59 The Texans fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +5% HOU HOU: Punt
2 Q1 10:52 The Texans were stopped on 3rd & 33rd & 4th downs · 37% expected +4% BUF HOU: Turnover on downs
3 Q1 10:10 The Texans were stopped on 4th & 33rd & 4th downs · 36% expected +13% BUF HOU: Turnover
4 Q1 7:09 The Texans were stopped on 3rd & 103rd & 4th downs · 22% expected +11% BUF HOU: Punt
5 Q1 3:59 The Bills converted 4th & 13rd & 4th downs · 76% expected +9% BUF BUF: Touchdown
6 Q1 2:06 The Bills converted 3rd & 23rd & 4th downs · 64% expected +5% BUF BUF: Touchdown
7 Q1 0:39 Offensive Holding on the Texans (Jordan Akins), 8 yards, wiping out the playJudgment calls · 5 flags in 1364 snaps before, position avg 1 per 269 +4% BUF BUF: Field goal
8 Q2 2:00 The Bills were stopped on 4th & 33rd & 4th downs · 54% expected +4% HOU BUF: 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.

  • Taron Johnson (BUF CB), out · 0.8 pts
  • Jordan Poyer (BUF SS), out · 0.6 pts
  • Jordan Poyer (BUF S), out · 0.5 pts
  • Jon Feliciano (BUF G), out · 0.3 pts
  • Deshaun Watson (HOU QB), out, replaced by d.mills · 8.3 pts
  • Zach Cunningham (HOU LB), out (IR) · 0.4 pts
  • Zach Cunningham (HOU ILB), 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

Texans 0% · Bills 100%

Final margin
Bills by 40
Luck in points
18.6 for the Bills
Luck-adjusted margin
Bills by 21.4
Replay with same day's form
Texans 2% · Bills 98% 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 2021 games · Texans · Bills

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