luckadjusted

Week 9 2020 · November 5, 2020

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

Packers at 49ers, Week 9 2020: who deserved to win?

The Packers beat the 49ers 34–17 and were the better team on the day: replayed with the same form, they win 7 of 10.

Before kickoff the Packers were 67% favorites. The biggest swing (Q2, 5:06 left): Defensive Too Many Men on Field on the 49ers, 5 yards, wiping out the play, worth 11 points of win probability to the Packers.

Final

Green Bay Packers 34
San Francisco 49ers 17

November 5, 2020 · Levi's Stadium · Closing line: Packers −6

Luck index +29 Packers lucky · −29 49ers

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. Packers win 7, 49ers win 3.

  1. 1 GB 43 SF 14
  2. 2 GB 47 SF 27
  3. 3 GB 19 SF 3
  4. 4 GB 31 SF 20
  5. 5 GB 27 SF 19
  6. 6 GB 24 SF 20
  7. 7 GB 28 SF 27
  8. 8 GB 21 SF 24
  9. 9 GB 13 SF 20
  10. 10 GB 24 SF 40

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

Packers win 71% of them, 49ers 29%, counting the 4% still level after regulation as half each. The line is what actually happened: Packers by 17.

Show as a table
Final margin in the replaysShare of replays
Packers by 17+24.8%
Packers by 9–1620.1%
Packers by 1–824.6%
Level after regulation4.3%
49ers by 1–814.3%
49ers by 9–167.0%
49ers by 17+4.9%

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 +13.3 points to the Packers: the final margin was Packers by 17, without the luck Packers by 3.7. 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.

  • R. Gould, 22 yds made · 98% expected
  • M. Crosby, 19 yds made · 100% expected
  • M. Crosby, 53 yds made · 68% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Packers 5 for 45 yards, 49ers 4 for 33 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 3:26 Neutral Zone Infraction on the Packers (Kingsley Keke), 5 yards · pre-snap +3% SF +1.1 pts
Q2 12:19 Offensive Holding on the 49ers (Richie James), 10 yards, wiping out the play +9% GB +1.6 pts
Q2 7:10 Defensive Pass Interference on the 49ers (Jason Verrett), 8 yards +4% GB +2.2 pts
Q2 5:06 Defensive Too Many Men on Field on the 49ers, 5 yards, wiping out the play · pre-snap +11% GB +4.7 pts
Q3 14:51 Defensive Pass Interference on the Packers (Josh Jackson), 5 yards +1% SF +0.8 pts
Q3 5:57 Unnecessary Roughness on the Packers (Josh Jackson), 15 yards 0% SF +1.6 pts
Q3 0:31 Offensive Holding on the 49ers, 10 yards 0% GB +1.6 pts
Q4 8:52 Illegal Formation on the Packers, 5 yards · pre-snap 0% SF +1.1 pts
Q4 0:53 Lowering the Head to Initiate Contact on the Packers, 15 yards, wiping out the play 0% SF +2.0 pts

Packers penalties, every game · 49ers penalties, every game · All teams, 2020

When it happened

49ers’ chance of winning

As low as 0% and as high as 58%. 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 Packers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 7:12 The Packers were stopped on 3rd & 53rd & 4th downs · 44% expected +4% SF GB: Punt
2 Q1 0:54 The 49ers were stopped on 3rd & 43rd & 4th downs · 38% expected +5% GB SF: Field goal
3 Q2 15:00 The Packers were stopped on 3rd & 43rd & 4th downs · 48% expected +5% SF GB: Punt
4 Q2 12:19 Offensive Holding on the 49ers (Richie James), 10 yards, wiping out the playJudgment calls · 1 flag in 526 snaps before, position avg 1 per 385 +9% GB GB: Touchdown
5 Q2 11:51 The 49ers were stopped on 3rd & 163rd & 4th downs · 21% expected +10% GB SF: Punt
6 Q2 9:11 The Packers converted 4th & 13rd & 4th downs · 76% expected +3% GB GB: Touchdown
7 Q2 7:10 Defensive Pass Interference on the 49ers (Jason Verrett), 8 yardsJudgment calls · 2 flags in 353 snaps before, position avg 1 per 207 +4% GB GB: Touchdown
8 Q2 5:06 Defensive Too Many Men on Field on the 49ers, 5 yards, wiping out the playPre-snap flags +11% GB GB: 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.

  • Jimmy Garoppolo (SF QB), out (IR), replaced by n.mullens · 3.8 pts
  • Brandon Aiyuk (SF WR), out (IR) · 1.4 pts
  • Trent Williams (SF T), out (IR) · 1.2 pts
  • George Kittle (SF TE), out (IR) · 1.2 pts
  • Deebo Samuel (SF WR), out (IR) · 1.0 pts
  • Kendrick Bourne (SF WR), out (IR) · 0.5 pts
  • Ben Garland (SF OL), out (IR) · 0.4 pts
  • David Bakhtiari (GB T), out · 1.4 pts
  • Allen Lazard (GB WR), out (IR) · 0.6 pts
  • Christian Kirksey (GB LB), out (IR) · 0.4 pts
  • Kevin King (GB CB), out · 0.4 pts
  • Kamal Martin (GB LB), out (IR) · 0.1 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

Packers 97% · 49ers 3%

Final margin
Packers by 17
Luck in points
13.3 for the Packers
Luck-adjusted margin
Packers by 3.7
Replay with same day's form
Packers 71% · 49ers 29% 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 9 2020 games · Packers · 49ers

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