luckadjusted

Week 6 2021 · October 18, 2021

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

Bills at Titans, Week 6 2021: who deserved to win?

The Titans beat the Bills 34–31, but it was a coin flip: replayed with the way both teams played, the Titans win 6 of 10. Luck ran their way: 3rd & 4th downs alone were worth 10 points of win probability to the Titans.

Before kickoff the Bills were 67% favorites. The biggest swing (Q4, 0:22 left): the Bills were stopped on 4th & 1, worth 40 points of win probability to the Titans.

Final

Buffalo Bills 31
Tennessee Titans 34

October 18, 2021 · Nissan Stadium · Closing line: Bills −6

Luck index +43 Titans lucky · −43 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. Bills win 4, Titans win 6.

  1. 1 BUF 30 TEN 10
  2. 2 BUF 23 TEN 13
  3. 3 BUF 34 TEN 28
  4. 4 BUF 26 TEN 24
  5. 5 BUF 31 TEN 34
  6. 6 BUF 28 TEN 33
  7. 7 BUF 9 TEN 17
  8. 8 BUF 22 TEN 34
  9. 9 BUF 24 TEN 41
  10. 10 BUF 10 TEN 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.

How 4,000 replays ended

Bills win 43% of them, Titans 57%, counting the 2% still level after regulation as half each. The line is what actually happened: Titans by 3.

Show as a table
Final margin in the replaysShare of replays
Bills by 17+7.3%
Bills by 9–1612.4%
Bills by 1–821.0%
Level after regulation2.4%
Titans by 1–826.2%
Titans by 9–1615.2%
Titans by 17+15.3%

Where the luck was

What the luck was worth

Every lucky and unlucky play, weighted by the moment it happened: its swing in win probability, added up by kind. A missed kick in a decided game counts for nothing; the same kick at the end of a tie game can be most of a win.

Swings add up across a game, so in one that went back and forth they can pass 100%. On the scoreboard the same luck was worth +6.4 points to the Bills: the final margin was Titans by 3, without the luck Titans by 9.4. Luck shares are the fitted ones (how much of each kind 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, 24 yds made · 98% expected
  • T. Bass, 28 yds made · 97% expected
  • R. Bullock, 43 yds made · 83% expected
  • T. Bass, 52 yds made · 69% expected
  • R. Bullock, 38 yds made · 90% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Bills 8 for 60 yards, Titans 7 for 91 yards

Every accepted flag, in order, and what it did to the helped team’s chance of winning at that moment, including any play it wiped out (points on the scoreboard in grey). A flag in a decided game is worth nothing; one at the turn of a close game can be worth most of a win. Judgment calls count toward luck, pre-snap fouls mostly don’t. How calls are valued

WhenFlagWin probability for
Q1 15:00 Offensive Holding on the Titans, 10 yards +1% BUF +0.9 pts
Q1 5:16 Offensive Holding on the Bills, 10 yards +2% TEN +0.9 pts
Q1 3:08 Illegal Forward Pass on the Titans (Chester Rogers), 5 yards 0% BUF +0.5 pts
Q1 2:54 Defensive Holding on the Bills (Tre'Davious White), 5 yards, wiping out the play +1% BUF +0.4 pts
Q2 13:10 Defensive Pass Interference on the Titans (Jackrabbit Jenkins), 7 yards +1% BUF +0.6 pts
Q2 13:06 Offensive Holding on the Bills (Emmanuel Sanders), 10 yards, wiping out the play +6% TEN +1.8 pts
Q2 10:37 Unnecessary Roughness on the Titans (David Long), 15 yards +6% BUF +1.8 pts
Q2 0:47 False Start on the Bills, 5 yards · pre-snap +4% TEN +0.5 pts
Q3 10:49 Illegal Use of Hands on the Bills (Jordan Poyer), 10 yards +3% TEN +1.0 pts
Q3 8:36 False Start on the Titans (Derrick Henry), 5 yards · pre-snap +4% BUF +0.6 pts
Q3 8:21 Neutral Zone Infraction on the Bills, 5 yards · pre-snap +4% TEN +0.7 pts
Q3 3:27 False Start on the Bills, 5 yards · pre-snap +3% TEN +1.1 pts
Q3 1:48 Defensive Pass Interference on the Titans, 39 yards +17% BUF +4.2 pts
Q4 11:41 Offensive Holding on the Titans, 10 yards, wiping out the play +13% BUF +1.9 pts
Q4 3:05 Offensive Holding on the Bills (Andre Smith), 10 yards +3% TEN +1.0 pts

Bills penalties, every game · Titans penalties, every game · All teams, 2021

When it happened

Titans’ chance of winning

As low as 21% 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 Titans were ahead in it, below while the Bills were.
#WhenWhat happenedWin probability forNext drive
1 Q1 1:12 The Titans were stopped on 3rd & 23rd & 4th downs · 62% expected +13% BUF TEN: Touchdown
2 Q2 7:02 The Titans converted 3rd & 83rd & 4th downs · 33% expected +12% TEN TEN: Field goal
3 Q2 0:47 The Bills converted 3rd & 123rd & 4th downs · 27% expectedFalse Start on the Bills, 5 yardsPre-snap flags +11% BUF BUF: Touchdown
4 Q3 6:28 The Titans converted 4th & 23rd & 4th downs · 62% expected +12% TEN TEN: Touchdown
5 Q3 1:48 Defensive Pass Interference on the Titans, 39 yardsJudgment calls +17% BUF BUF: Touchdown
6 Q4 11:41 Offensive Holding on the Titans, 10 yards, wiping out the playJudgment calls +13% BUF BUF: Punt
7 Q4 4:35 The Titans converted 3rd & 63rd & 4th downs · 39% expected +16% TEN TEN: Touchdown
8 Q4 0:22 The Bills were stopped on 4th & 13rd & 4th downs · 69% expected +40% TEN –

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.

  • Kristian Fulton (TEN CB), out (IR) · 0.5 pts
  • Brett Kern (TEN P), out (IR) · 0.2 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

Bills 10% · Titans 90%

Final margin
Titans by 3
Luck in points
6.4 for the Bills
Luck-adjusted margin
Titans by 9.4
Replay with same day's form
Bills 43% · Titans 57% 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 6 2021 games · Bills · Titans

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