luckadjusted

Week 1 2021 · September 12, 2021

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

Jaguars at Texans, Week 1 2021: who deserved to win?

The Texans beat the Jaguars 37–21, and it was no fluke: replayed with the way both teams actually played, the Texans win 8 of 10. The Jaguars had the bounces: injuries alone were worth 7.7 points to the Jaguars.

An off day for the Jaguars: they played far below what the matchup promised. In a fresh game against the Texans they would win 48% of the time; with this day’s form, 17%. The numbers

Before kickoff the Jaguars were 60% favorites. The biggest swing (Q1, 8:18 left): the Texans converted 3rd & 9, worth 17 points of win probability to the Texans.

Final

Jacksonville Jaguars 21
Houston Texans 37

September 12, 2021 · NRG Stadium · Closing line: Jaguars −3.5

Luck index +17 Texans about even · −17 Jaguars

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. Jaguars win 2, Texans win 8.

  1. 1 JAX 51 HOU 37
  2. 2 JAX 23 HOU 20
  3. 3 JAX 34 HOU 37
  4. 4 JAX 21 HOU 26
  5. 5 JAX 28 HOU 37
  6. 6 JAX 27 HOU 39
  7. 7 JAX 10 HOU 26
  8. 8 JAX 10 HOU 30
  9. 9 JAX 24 HOU 47
  10. 10 JAX 19 HOU 51

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 Jaguars

They played far below what the matchup promised. In a fresh game against the Texans they would win 48% of the time; with this day’s form, 17%.

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

UnitThis gameUsual levelBetter or worse than usual
Jaguars offenseEPA per play gained +0.10 +0.07 better by 0.03
Jaguars defenseEPA per play allowed +0.29 +0.21 worse by 0.08
Texans offenseEPA per play gained +0.29 +0.17 better by 0.11
Texans defenseEPA per play allowed +0.10 +0.21 better by 0.10

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

Jaguars win 17% of them, Texans 83%, counting the 1% still level after regulation as half each. The line is what actually happened: Texans by 16.

Show as a table
Final margin in the replaysShare of replays
Jaguars by 17+2.1%
Jaguars by 9–164.3%
Jaguars by 1–89.8%
Level after regulation1.3%
Texans by 1–819.6%
Texans by 9–1621.5%
Texans by 17+41.5%

Where the luck was

Take the luck out

The final margin was Texans by 16. Remove the luck, one kind at a time, and it becomes Texans by 15.6.

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. Lambo, 55 yds missed · 70% expected
  • J. Slye, 40 yds made · 88% expected
  • J. Slye, 26 yds made · 98% expected
  • J. Slye, 25 yds made · 98% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Texans’ chance of winning

As low as 47% 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 Texans were ahead in it, below while the Jaguars were.
#WhenWhat happenedWin probability forNext drive
1 Q1 14:25 The Texans were stopped on 3rd & 43rd & 4th downs · 45% expected +5% JAX HOU: Punt
2 Q1 8:18 The Texans converted 3rd & 93rd & 4th downs · 29% expected +17% HOU HOU: Touchdown
3 Q1 6:02 Offensive Holding on the Jaguars, 10 yards, wiping out the playJudgment calls +5% HOU HOU: Touchdown
4 Q1 4:48 The Jaguars were stopped on 3rd & 53rd & 4th downs · 40% expected +4% HOU JAX: Missed field goal
5 Q1 4:44 J. Lambo missed 55-yard field goalKicks · 70% expected for him, 9 of 10 from 45+ before +8% HOU JAX: Touchdown
6 Q2 15:00 The Jaguars converted 3rd & 173rd & 4th downs · 18% expected +5% JAX JAX: Touchdown
7 Q2 13:06 Roughing the Passer on the Texans (Maliek Collins), 15 yardsJudgment calls · 9 flags in 1402 snaps before, position avg 1 per 273 +5% JAX JAX: Touchdown
8 Q2 8:15 The Texans were stopped on 3rd & 33rd & 4th downs · 52% expected +4% JAX HOU: 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.

  • Deshaun Watson (HOU QB), out, replaced by ty.taylor · 8.3 pts
  • Charlie Heck (HOU T), out (IR) · 0.3 pts
  • Ka'imi Fairbairn (HOU K), out (IR) · 0.3 pts
  • Tre Herndon (JAX CB), out · 0.6 pts
  • Adam Gotsis (JAX DE), out · 0.4 pts
  • Daniel Thomas (JAX S), out · 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

Jaguars 9% · Texans 91%

Final margin
Texans by 16
Luck in points
0.4 for the Texans
Luck-adjusted margin
Texans by 15.6
Replay with same day's form
Jaguars 17% · Texans 83% 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 · Jaguars · Texans

More from Week 1 2021