luckadjusted

Week 1 2023 · September 10, 2023

Rams at Seahawks, Week 1 2023: who deserved to win?

The Rams beat the Seahawks 30–13 and were the better team on the day: replayed with the same form, they win 7 of 10. The Seahawks had the bounces: judgment calls alone were worth 11 points of win probability to the Seahawks.

Before kickoff the Seahawks were 63% favorites. The biggest swing (Q3, 10:35 left): the Rams converted 3rd & 8, worth 16 points of win probability to the Rams.

Final

Los Angeles Rams 30
Seattle Seahawks 13

September 10, 2023 · Lumen Field · Closing line: Seahawks −4.5

Luck index +33 Rams lucky · −33 Seahawks

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. Rams win 7, Seahawks win 3.

  1. 1 LA 30 SEA 6
  2. 2 LA 17 SEA 0
  3. 3 LA 20 SEA 6
  4. 4 LA 17 SEA 7
  5. 5 LA 20 SEA 13
  6. 6 LA 23 SEA 19
  7. 7 LA 16 SEA 14
  8. 8 LA 14 SEA 17
  9. 9 LA 14 SEA 20
  10. 10 LA 10 SEA 25

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

Rams win 67% of them, Seahawks 33%, counting the 2% still level after regulation as half each. The line is what actually happened: Rams by 17.

Show as a table
Final margin in the replaysShare of replays
Rams by 17+15.4%
Rams by 9–1621.3%
Rams by 1–829.1%
Level after regulation2.4%
Seahawks by 1–820.1%
Seahawks by 9–168.7%
Seahawks by 17+3.0%

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 +3.2 points to the Rams: the final margin was Rams by 17, without the luck Rams by 13.8. 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.

  • J. Myers, 36 yds made · 92% expected
  • J. Myers, 42 yds made · 84% expected
  • B. Maher, 57 yds blocked · 57% expected
  • J. Myers, 39 yds missed · 88% expected
  • B. Maher, 56 yds missed · 58% expected
  • B. Maher, 38 yds made · 88% expected
  • B. Maher, 54 yds made · 60% expected
  • B. Maher, 45 yds made · 76% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Rams 7 for 53 yards, Seahawks 7 for 55 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 11:17 Defensive Pass Interference on the Rams, 10 yards +5% SEA +1.5 pts
Q1 2:16 Illegal Block Above the Waist on the Rams (Van Jefferson), 10 yards +1% SEA +1.0 pts
Q2 9:16 Face Mask on the Rams, 15 yards +4% SEA +1.3 pts
Q2 9:16 Offside on Free Kick on the Seahawks, 5 yards · pre-snap +2% LA +0.5 pts
Q2 9:11 Delay of Game on the Rams, 5 yards · pre-snap +1% SEA +0.4 pts
Q2 1:45 Defensive Pass Interference on the Rams, 3 yards +1% SEA +0.3 pts
Q3 8:56 Offside on Free Kick on the Rams (Ben Skowronek), 5 yards · pre-snap +1% SEA +0.4 pts
Q3 2:08 Defensive Pass Interference on the Rams (Derion Kendrick), 5 yards +5% SEA +1.3 pts
Q4 11:16 Illegal Use of Hands on the Seahawks (Tre Brown), 5 yards +4% LA +1.8 pts
Q4 9:19 Illegal Formation on the Seahawks, 5 yards · pre-snap +1% LA +0.5 pts
Q4 4:35 Taunting on the Seahawks (D.K. Metcalf), 15 yards +1% LA +1.3 pts
Q4 2:31 Unnecessary Roughness on the Seahawks (Quandre Diggs), 15 yards 0% LA +2.1 pts
Q4 2:22 Encroachment on the Seahawks (Jarran Reed), 5 yards · pre-snap 0% SEA +0.6 pts
Q4 2:00 Encroachment on the Seahawks (Dre'Mont Jones), 5 yards · pre-snap 0% LA +0.4 pts

Rams penalties, every game · Seahawks penalties, every game · All teams, 2023

When it happened

Seahawks’ chance of winning

As low as 0% and as high as 82%. 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 Seahawks were ahead in it, below while the Rams were.
#WhenWhat happenedWin probability forNext drive
1 Q1 12:29 The Seahawks converted 3rd & 23rd & 4th downs · 60% expected +8% SEA SEA: Field goal
2 Q1 5:10 The Rams converted 3rd & 103rd & 4th downs · 29% expected +7% LA LA: Touchdown
3 Q2 1:54 B. Maher had a 57-yard field goal blockedKicks · 57% expected for him, 17 of 27 from 45+ before +9% SEA LA: Missed field goal
4 Q2 0:36 J. Myers missed 39-yard field goalKicks · 88% expected for him +10% LA SEA: Punt
5 Q2 0:22 The Rams converted 3rd & 103rd & 4th downs · 29% expected +6% LA LA: Missed field goal
6 Q2 0:05 B. Maher missed 56-yard field goalKicks · 58% expected for him, 17 of 28 from 45+ before +10% SEA LA: Touchdown
7 Q3 10:35 The Rams converted 3rd & 83rd & 4th downs · 34% expected +16% LA LA: Touchdown
8 Q4 9:49 The Rams converted 4th & 13rd & 4th downs · 68% expected +9% LA LA: Touchdown

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

Rams 97% · Seahawks 3%

Final margin
Rams by 17
Luck in points
3.2 for the Rams
Luck-adjusted margin
Rams by 13.8
Replay with same day's form
Rams 67% · Seahawks 33% 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; injuries from snap counts and injury reports.

Methodology and validation · All Week 1 2023 games · Rams · Seahawks

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