luckadjusted

Week 1 2020 · September 13, 2020

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

Cowboys at Rams, Week 1 2020: who deserved to win?

The Rams beat the Cowboys 20–17, but it was a coin flip: replayed with the way both teams played, the Rams win 5 of 10. Luck ran their way: judgment calls alone were worth 96 points of win probability to the Rams.

Before kickoff it was a pick’em. The biggest swing (Q4, 0:31 left): Offensive Pass Interference on the Cowboys (Michael Gallup), 10 yards, wiping out the play, worth 94 points of win probability to the Rams.

Final

Dallas Cowboys 17
Los Angeles Rams 20

September 13, 2020 · SoFi Stadium · Closing line: Rams −1

Luck index +45 Rams lucky · −45 Cowboys

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. Cowboys win 5, Rams win 5.

  1. 1 DAL 44 LA 23
  2. 2 DAL 41 LA 27
  3. 3 DAL 30 LA 20
  4. 4 DAL 24 LA 19
  5. 5 DAL 27 LA 24
  6. 6 DAL 31 LA 34
  7. 7 DAL 20 LA 27
  8. 8 DAL 34 LA 44
  9. 9 DAL 14 LA 29
  10. 10 DAL 10 LA 33

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

Cowboys win 45% of them, Rams 55%, counting the 5% still level after regulation as half each. The line is what actually happened: Rams by 3.

Show as a table
Final margin in the replaysShare of replays
Cowboys by 17+9.8%
Cowboys by 9–1613.2%
Cowboys by 1–821.8%
Level after regulation5.3%
Rams by 1–822.5%
Rams by 9–1615.2%
Rams by 17+12.3%

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 +8.7 points to the Rams: the final margin was Rams by 3, without the luck Cowboys by 5.7. 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.

  • S. Sloman, 29 yds missed · 97% expected
  • S. Sloman, 35 yds made · 93% expected
  • G. Zuerlein, 53 yds missed · 69% expected
  • S. Sloman, 31 yds made · 96% expected
  • G. Zuerlein, 33 yds made · 94% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Cowboys 7 for 50 yards, Rams 5 for 34 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 Neutral Zone Infraction on the Cowboys (DeMarcus Lawrence), 5 yards · pre-snap +1% LA +0.5 pts
Q1 8:16 Neutral Zone Infraction on the Cowboys (Everson Griffen), 5 yards · pre-snap +2% LA +0.7 pts
Q2 15:00 Illegal Block Above the Waist on the Cowboys (CeeDee Lamb), 10 yards +3% LA +0.9 pts
Q2 12:45 False Start on the Cowboys, 5 yards · pre-snap +1% LA +0.8 pts
Q2 9:00 Intentional Grounding on the Rams (Jared Goff), 10 yards +2% DAL +0.9 pts
Q2 8:54 Neutral Zone Infraction on the Cowboys (Everson Griffen), 5 yards · pre-snap 0% DAL +0.4 pts
Q2 1:02 Offensive Pass Interference on the Cowboys (Dalton Schultz), 10 yards, wiping out the play +10% LA +2.5 pts
Q3 9:49 Ineligible Downfield Pass on the Rams, 5 yards, wiping out the play +9% DAL +1.9 pts
Q3 3:11 Defensive Pass Interference on the Rams (Micah Kiser), 4 yards +3% DAL +0.6 pts
Q3 0:31 False Start on the Rams (Justin Hollins), 5 yards · pre-snap +4% DAL +0.7 pts
Q4 7:41 Illegal Block Above the Waist on the Rams (Robert Woods), 10 yards +4% DAL +0.8 pts
Q4 0:31 Offensive Pass Interference on the Cowboys (Michael Gallup), 10 yards, wiping out the play +94% LA +5.2 pts

Cowboys penalties, every game · Rams penalties, every game · All teams, 2020

When it happened

Rams’ chance of winning

As low as 40% 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 Rams were ahead in it, below while the Cowboys were.
#WhenWhat happenedWin probability forNext drive
1 Q2 5:17 G. Zuerlein missed 53-yard field goalKicks · 69% expected for him, 9 of 13 from 45+ before +12% LA DAL: Touchdown
2 Q2 1:02 Offensive Pass Interference on the Cowboys (Dalton Schultz), 10 yards, wiping out the playJudgment calls · 4 flags in 212 snaps before, position avg 1 per 276 +10% LA LA: End of half
3 Q3 13:34 The Cowboys converted 3rd & 103rd & 4th downs · 29% expected +9% DAL DAL: Punt
4 Q3 9:49 Ineligible Downfield Pass on the Rams, 5 yards, wiping out the playJudgment calls +9% DAL DAL: Punt
5 Q3 1:58 The Cowboys were stopped on 3rd & 63rd & 4th downs · 39% expected +7% LA DAL: Field goal
6 Q4 11:46 The Cowboys were stopped on 4th & 33rd & 4th downs · 53% expected +19% LA DAL: Punt
7 Q4 7:41 The Rams were stopped on 3rd & 23rd & 4th downs · 60% expectedIllegal Block Above the Waist on the Rams (Robert Woods), 10 yardsJudgment calls · 4 flags in 988 snaps before, position avg 1 per 385 +10% DAL LA: Punt
8 Q4 0:31 Offensive Pass Interference on the Cowboys (Michael Gallup), 10 yards, wiping out the playJudgment calls · 1 flag in 846 snaps before, position avg 1 per 385 +94% LA LA: End of game

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.

  • La'el Collins (DAL T), out (IR) · 0.6 pts
  • Jourdan Lewis (DAL CB), out · 0.4 pts
  • Sean Lee (DAL LB), out (IR) · 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

Cowboys 69% · Rams 31%

Final margin
Rams by 3
Luck in points
8.7 for the Rams
Luck-adjusted margin
Cowboys by 5.7
Replay with same day's form
Cowboys 45% · Rams 55% 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 2020 games · Cowboys · Rams

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