luckadjusted

Week 15 2019 · December 15, 2019

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

Rams at Cowboys, Week 15 2019: who deserved to win?

The Cowboys beat the Rams 44–21, and it was no fluke: replayed with the way both teams actually played, the Cowboys win 9 of 10.

Before kickoff it was a pick’em.

Final

Los Angeles Rams 21
Dallas Cowboys 44

December 15, 2019 · AT&T Stadium · Closing line: Rams −1

Luck index +8 Cowboys about even · −8 Rams

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 1, Cowboys win 9.

  1. 1 LA 23 DAL 16
  2. 2 LA 14 DAL 17
  3. 3 LA 29 DAL 34
  4. 4 LA 28 DAL 36
  5. 5 LA 16 DAL 27
  6. 6 LA 24 DAL 37
  7. 7 LA 16 DAL 33
  8. 8 LA 17 DAL 38
  9. 9 LA 23 DAL 48
  10. 10 LA 21 DAL 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

Rams win 8% of them, Cowboys 92%, counting the 1% still level after regulation as half each. The line is what actually happened: Cowboys by 23.

Show as a table
Final margin in the replaysShare of replays
Rams by 17+0.4%
Rams by 9–162.3%
Rams by 1–84.6%
Level after regulation0.8%
Cowboys by 1–814.9%
Cowboys by 9–1622.4%
Cowboys by 17+54.7%

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 +8.9 points to the Cowboys: the final margin was Cowboys by 23, without the luck Cowboys by 14.1. 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.

  • K. Forbath, 50 yds made · 75% expected
  • K. Forbath, 42 yds made · 87% expected
  • K. Forbath, 42 yds made · 87% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Rams 5 for 29 yards, Cowboys 4 for 16 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 14:49 Defensive Holding on the Cowboys (Robert Quinn), 5 yards +6% LA +1.8 pts
Q1 12:57 Delay of Game on the Rams, 5 yards · pre-snap +3% DAL +0.4 pts
Q1 9:59 Neutral Zone Infraction on the Cowboys (Maliek Collins), 5 yards · pre-snap +5% LA +0.7 pts
Q1 9:14 Illegal Shift on the Rams (Josh Reynolds), 5 yards · pre-snap +3% DAL +0.7 pts
Q2 1:57 Offensive Holding on the Rams, 10 yards, wiping out the play +4% DAL +2.2 pts
Q2 0:26 Illegal Use of Hands on the Rams (Michael Brockers), 4 yards +1% DAL +1.8 pts
Q4 4:55 False Start on the Rams, 5 yards · pre-snap 0% DAL +0.8 pts
Q4 4:33 Defensive Offside on the Cowboys, 5 yards, wiping out the play · pre-snap 0% LA +4.4 pts
Q4 3:17 Defensive Offside on the Cowboys, 1 yard · pre-snap 0% LA 0.0 pts

Rams penalties, every game · Cowboys penalties, every game · All teams, 2019

When it happened

Cowboys’ chance of winning

As low as 50% 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 Cowboys were ahead in it, below while the Rams were.
#WhenWhat happenedWin probability forNext drive
1 Q1 14:49 Defensive Holding on the Cowboys (Robert Quinn), 5 yardsJudgment calls · 2 flags in 553 snaps before, position avg 1 per 249 +6% LA LA: Punt
2 Q1 11:08 The Cowboys were stopped on 3rd & 33rd & 4th downs · 55% expected +4% LA DAL: Punt
3 Q1 9:59 Neutral Zone Infraction on the Cowboys (Maliek Collins), 5 yardsPre-snap flags · 4 flags in 693 snaps before, position avg 1 per 242 +4% LA LA: Punt
4 Q1 5:01 The Cowboys converted 3rd & 93rd & 4th downs · 32% expected +6% DAL DAL: Touchdown
5 Q1 1:53 The Cowboys converted 3rd & 103rd & 4th downs · 31% expected +7% DAL DAL: Touchdown
6 Q2 13:03 The Rams converted 3rd & 23rd & 4th downs · 51% expected +6% LA LA: Touchdown
7 Q2 8:45 The Cowboys converted 3rd & 43rd & 4th downs · 49% expected +5% DAL DAL: Touchdown
8 Q2 1:57 Offensive Holding on the Rams, 10 yards, wiping out the playJudgment calls +4% DAL DAL: 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.

  • Leighton Vander Esch (DAL LB), out · 0.5 pts
  • Connor Williams (DAL G), out (IR) · 0.4 pts
  • Rob Havenstein (LA T), out · 1.0 pts
  • Gerald Everett (LA TE), out · 0.5 pts
  • Brian Allen (LA C), 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

Rams 0% · Cowboys 100%

Final margin
Cowboys by 23
Luck in points
8.9 for the Cowboys
Luck-adjusted margin
Cowboys by 14.1
Replay with same day's form
Rams 8% · Cowboys 92% 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 15 2019 games · Rams · Cowboys

More from Week 15 2019