luckadjusted

Week 6 2020 · October 18, 2020

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

Rams at 49ers, Week 6 2020: who deserved to win?

The 49ers beat the Rams 24–16, but it was a coin flip: replayed with the way both teams played, the 49ers win 5 of 10. Luck ran their way: kicks alone were worth 1.8 points to the 49ers.

Before kickoff the Rams were 56% favorites. The biggest swing (Q2, 14:21 left): the 49ers converted 4th & 2, worth 12 points of win probability to the 49ers.

Final

Los Angeles Rams 16
San Francisco 49ers 24

October 18, 2020 · Levi's Stadium · Closing line: Rams −2

Luck index +45 49ers lucky · −45 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 5, 49ers win 5.

  1. 1 LA 31 SF 10
  2. 2 LA 23 SF 10
  3. 3 LA 25 SF 16
  4. 4 LA 25 SF 20
  5. 5 LA 23 SF 21
  6. 6 LA 25 SF 27
  7. 7 LA 31 SF 37
  8. 8 LA 15 SF 25
  9. 9 LA 22 SF 37
  10. 10 LA 10 SF 31

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 45% of them, 49ers 55%, counting the 6% still level after regulation as half each. The line is what actually happened: 49ers by 8.

Show as a table
Final margin in the replaysShare of replays
Rams by 17+9.6%
Rams by 9–1612.7%
Rams by 1–822.0%
Level after regulation6.4%
49ers by 1–822.0%
49ers by 9–1614.7%
49ers by 17+12.7%

Where the luck was

Take the luck out

The final margin was 49ers by 8. Remove the luck, one kind at a time, and it becomes 49ers by 11.0.

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.

  • S. Sloman, 42 yds made · 83% expected
  • R. Gould, 49 yds made · 67% expected
  • Extra point missed · 93% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

49ers’ chance of winning

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 49ers were ahead in it, below while the Rams were.
#WhenWhat happenedWin probability forNext drive
1 Q2 14:21 The 49ers converted 4th & 23rd & 4th downs · 61% expected +12% SF SF: Touchdown
2 Q2 13:44 The Rams converted 3rd & 93rd & 4th downs · 30% expected +4% LA LA: Touchdown
3 Q2 9:53 Offensive Holding on the Rams, 10 yards, wiping out the playJudgment calls +5% SF SF: Touchdown
4 Q2 9:08 The Rams converted 3rd & 103rd & 4th downs · 22% expected +9% LA LA: Touchdown
5 Q2 9:03 The Rams missed an extra pointKicks · extra points are made about 94% of the time +5% SF LA: Punt
6 Q2 7:05 Offensive Holding on the 49ers (Brandon Aiyuk), 10 yards, wiping out the playJudgment calls · 0 flags in 226 snaps before, position avg 1 per 385 +5% LA LA: Punt
7 Q3 2:43 The Rams were stopped on 3rd & 23rd & 4th downs · 53% expected +4% SF LA: Turnover
8 Q3 2:39 The Rams were stopped on 4th & 23rd & 4th downs · 53% expected +4% SF LA: Punt

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.

  • Richard Sherman (SF CB), out (IR) · 1.6 pts
  • Nick Bosa (SF DE), out (IR) · 1.1 pts
  • K'Waun Williams (SF CB), out (IR) · 0.4 pts
  • Kwon Alexander (SF LB), out · 0.4 pts
  • Dontae Johnson (SF CB), out · 0.3 pts
  • Dee Ford (SF LB), out (IR) · 0.1 pts
  • Jordan Fuller (LA S), out (IR) · 0.4 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 8% · 49ers 92%

Final margin
49ers by 8
Luck in points
3.0 for the Rams
Luck-adjusted margin
49ers by 11.0
Replay with same day's form
Rams 45% · 49ers 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 6 2020 games · Rams · 49ers

More from Week 6 2020