luckadjusted

Week 1 2021 · September 12, 2021

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

Cardinals at Titans, Week 1 2021: who deserved to win?

The Cardinals beat the Titans 38–13 and were the better team on the day: replayed with the same form, they win 8 of 10.

Before kickoff the Titans were 57% favorites. The biggest swing (Q1, 8:18 left): the Cardinals converted 3rd & 5, worth 10 points of win probability to the Cardinals.

Final

Arizona Cardinals 38
Tennessee Titans 13

September 12, 2021 · Nissan Stadium · Closing line: Titans −2.5

Luck index +22 Cardinals about even · −22 Titans

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. Cardinals win 8, Titans win 2.

  1. 1 ARI 31 TEN 3
  2. 2 ARI 27 TEN 5
  3. 3 ARI 30 TEN 13
  4. 4 ARI 34 TEN 19
  5. 5 ARI 29 TEN 17
  6. 6 ARI 26 TEN 17
  7. 7 ARI 26 TEN 19
  8. 8 ARI 16 TEN 13
  9. 9 ARI 28 TEN 31
  10. 10 ARI 38 TEN 55

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

Cardinals win 78% of them, Titans 22%, counting the 2% still level after regulation as half each. The line is what actually happened: Cardinals by 25.

Show as a table
Final margin in the replaysShare of replays
Cardinals by 17+33.9%
Cardinals by 9–1619.5%
Cardinals by 1–822.7%
Level after regulation2.3%
Titans by 1–811.7%
Titans by 9–166.3%
Titans by 17+3.7%

Where the luck was

Take the luck out

The final margin was Cardinals by 25. Remove the luck, one kind at a time, and it becomes Cardinals by 17.3.

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.

  • M. Prater, 34 yds made · 93% expected
  • M. Badgley, 46 yds missed · 70% expected
  • M. Prater, 43 yds missed · 82% expected
  • Extra point missed · 93% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Titans’ chance of winning

As low as 0% and as high as 55%. 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 Cardinals were.
#WhenWhat happenedWin probability forNext drive
1 Q1 8:36 The Titans fumbled and the Cardinals recoveredFumble bounces · loose balls are close to 50/50 +5% ARI TEN: Punt
2 Q1 8:18 The Cardinals converted 3rd & 53rd & 4th downs · 34% expected +10% ARI ARI: Touchdown
3 Q1 3:10 The Titans converted 4th & 43rd & 4th downs · 43% expected +5% TEN TEN: Punt
4 Q2 14:20 Defensive Pass Interference on the Titans (Jackrabbit Jenkins), 17 yardsJudgment calls · 14 flags in 1984 snaps before, position avg 1 per 213 +4% ARI ARI: Touchdown
5 Q2 8:43 The Titans converted 3rd & 103rd & 4th downs · 26% expected +5% TEN TEN: Touchdown
6 Q2 3:04 The Cardinals converted 3rd & 63rd & 4th downs · 39% expected +4% ARI ARI: Touchdown
7 Q2 0:19 M. Badgley missed 46-yard field goalKicks · 70% expected for him, 6 of 16 from 45+ before +4% ARI TEN: Touchdown
8 Q3 13:54 The Cardinals were stopped on 3rd & 33rd & 4th downs · 54% expected +5% TEN ARI: 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.

  • David Long (TEN LB), out · 0.3 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

Cardinals 100% · Titans 0%

Final margin
Cardinals by 25
Luck in points
7.7 for the Cardinals
Luck-adjusted margin
Cardinals by 17.3
Replay with same day's form
Cardinals 78% · Titans 22% 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 · Cardinals · Titans

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