luckadjusted
NFL Week 9 · 2026

Week 1 2023 · September 10, 2023

Jaguars at Colts, Week 1 2023: who deserved to win?

The Jaguars beat the Colts 31–21, and the replays back it up: with the way both teams actually played, the Jaguars win 10 of 10.

An off day for the Colts: their offense played far below its usual level. In a fresh game against the Jaguars they would win 40% of the time; with this day’s form, 4%. The numbers

Before kickoff the Jaguars were 62% favorites. The biggest swing (Q3, 2:41 left): Return touchdown by the Colts, worth 26 points of win probability to the Colts.

Final

Jacksonville Jaguars 31
Indianapolis Colts 21

September 10, 2023 · Lucas Oil Stadium · Closing line: Jaguars −4

Luck index +4 Jaguars about even · −4 Colts

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 10, Colts win 0.

  1. 1 JAX 57 IND 17
  2. 2 JAX 44 IND 13
  3. 3 JAX 33 IND 6
  4. 4 JAX 33 IND 10
  5. 5 JAX 50 IND 30
  6. 6 JAX 47 IND 30
  7. 7 JAX 44 IND 30
  8. 8 JAX 41 IND 31
  9. 9 JAX 33 IND 26
  10. 10 JAX 12 IND 9

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 Colts

Their offense played far below its usual level. In a fresh game against the Jaguars they would win 40% of the time; with this day’s form, 4%.

36 points apart for the Colts: 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 +0.00 +0.13 worse by 0.13
Jaguars defenseEPA per play allowed −0.21 +0.12 better by 0.33
Colts offenseEPA per play gained −0.21 +0.04 worse by 0.25
Colts defenseEPA per play allowed +0.00 +0.06 better by 0.06

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 96% of them, Colts 4%. The line is what actually happened: Jaguars by 10.

Show as a table
Final margin in the replaysShare of replays
Jaguars by 17+75.1%
Jaguars by 9–1615.3%
Jaguars by 1–86.0%
Level after regulation0.4%
Colts by 1–82.4%
Colts by 9–160.6%
Colts by 17+0.1%

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 +7.4 points to the Jaguars: the final margin was Jaguars by 10, without the luck Jaguars by 2.6. Luck shares are the fitted ones (how much of each kind is luck).

Penalties: Jaguars 4 for 45 yards, Colts 4 for 35 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 half toward luck; pre-snap fouls, which repeat, don’t count. How calls are valued

WhenFlagWin probability for
Q2 13:47 Defensive Holding on the Colts (DeForest Buckner), 5 yards +2% JAX +0.9 pts
Q2 9:40 False Start on the Colts (Alec Pierce), 5 yards · pre-snap +3% JAX +0.8 pts
Q2 4:43 Unnecessary Roughness on the Jaguars (Andre Cisco), 15 yards +4% IND +1.8 pts
Q3 13:38 Unnecessary Roughness on the Jaguars (Devin Lloyd), 15 yards +2% IND +1.0 pts
Q3 12:28 Illegal Blindside Block on the Colts, 15 yards +5% JAX +1.4 pts
Q3 3:10 Offensive Holding on the Jaguars, 10 yards, wiping out the play +12% IND +3.1 pts
Q3 1:03 Offensive Holding on the Colts (Michael Pittman Jr.), 10 yards, wiping out the play +8% JAX +1.7 pts
Q4 11:31 Defensive Offside on the Jaguars (Travon Walker), 5 yards · pre-snap +1% IND +0.2 pts

Jaguars penalties, every game · Colts penalties, every game · All teams, 2023

When it happened

Colts’ chance of winning

As low as 0% and as high as 81%. 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 Colts were ahead in it, below while the Jaguars were.
#WhenWhat happenedWin probability forNext drive
1 Q2 13:19 The Jaguars were intercepted on a well-placed throwInterceptions · defenses pick off well under 1% of clean throws +9% IND JAX: Punt
2 Q3 4:29 The Jaguars were stopped on 4th & 13rd & 4th downs · 74% expected +13% IND JAX: Opp touchdown
3 Q3 3:10 Offensive Holding on the Jaguars, 10 yards, wiping out the playJudgment calls +12% IND IND: Opp touchdown
4 Q3 2:41 The Jaguars fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50Return touchdown by the ColtsSpecial teams +26% IND JAX: Punt
5 Q3 1:03 Offensive Holding on the Colts (Michael Pittman Jr.), 10 yards, wiping out the playJudgment calls · 13 flags in 2846 snaps before, position avg 1 per 420 +8% JAX JAX: Turnover on downs
6 Q4 13:01 The Jaguars were stopped on 4th & 13rd & 4th downs · 74% expected +9% IND JAX: Touchdown
7 Q4 7:26 The Jaguars converted 4th & 23rd & 4th downs · 61% expected +12% JAX JAX: Touchdown
8 Q4 5:09 The Colts threw an interception-worthy pass, and it was pickedInterceptions · defenses catch 49% of interception-worthy throws +9% JAX IND: Turnover on downs

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.

  • Jonathan Taylor (IND RB), out (IR) · 0.6 pts
  • Jelani Woods (IND TE), out (IR) · 0.2 pts
  • Cam Robinson (JAX T), out (IR) · 0.8 pts
  • Dawuane Smoot (JAX DE), 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

Jaguars 66% · Colts 34%

Final margin
Jaguars by 10
Luck in points
7.4 for the Jaguars
Luck-adjusted margin
Jaguars by 2.6
Replay with same day's form
Jaguars 96% · Colts 4% unchanged: why
How much of each is luck?

0% treats it as skill, 100% as pure luck. The tick is our fit.

What counts

None by default: our tests measured no carryover after a lucky break. Slide it up to count a break for more than its own swing. 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; injuries from snap counts and injury reports.

Methodology and validation · All Week 1 2023 games · Jaguars · Colts

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