luckadjusted

Week 11 2021 · November 21, 2021

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

49ers at Jaguars, Week 11 2021: who deserved to win?

The 49ers beat the Jaguars 30–10, and it was no fluke: replayed with the way both teams actually played, the 49ers win 9 of 10. The Jaguars had the bounces: kicks alone were worth 13 points of win probability to the Jaguars.

Before kickoff the 49ers were 68% favorites. The biggest swing (Q1, 1:59 left): R. Gould made 20-yard field goal, worth 13 points of win probability to the Jaguars.

Final

San Francisco 49ers 30
Jacksonville Jaguars 10

November 21, 2021 · TIAA Bank Stadium · Closing line: 49ers −6.5

Luck index +9 49ers about even · −9 Jaguars

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. 49ers win 9, Jaguars win 1.

  1. 1 SF 35 JAX 7
  2. 2 SF 34 JAX 13
  3. 3 SF 24 JAX 6
  4. 4 SF 16 JAX 0
  5. 5 SF 30 JAX 17
  6. 6 SF 13 JAX 3
  7. 7 SF 17 JAX 10
  8. 8 SF 17 JAX 13
  9. 9 SF 16 JAX 14
  10. 10 SF 3 JAX 9

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

49ers win 91% of them, Jaguars 9%, counting the 1% still level after regulation as half each. The line is what actually happened: 49ers by 20.

Show as a table
Final margin in the replaysShare of replays
49ers by 17+42.4%
49ers by 9–1628.1%
49ers by 1–819.5%
Level after regulation1.4%
Jaguars by 1–86.9%
Jaguars by 9–161.6%
Jaguars by 17+0.2%

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 +10.5 points to the 49ers: the final margin was 49ers by 20, without the luck 49ers by 9.5. 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, 20 yds made · 98% expected
  • M. Wright, 30 yds made · 95% expected
  • R. Gould, 48 yds made · 66% expected
  • R. Gould, 45 yds made · 72% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: 49ers 1 for 12 yards, Jaguars 8 for 56 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 9:11 Defensive Holding on the Jaguars (Rayshawn Jenkins), 5 yards +5% SF +2.0 pts
Q1 3:46 Defensive Offside on the Jaguars (Dawuane Smoot), 5 yards · pre-snap +5% SF +1.1 pts
Q2 9:58 Disqualification on the Jaguars (Rayshawn Jenkins), 14 yards +4% SF +1.6 pts
Q2 8:48 Roughing the Passer on the Jaguars (K'Lavon Chaisson), 7 yards +2% SF +0.9 pts
Q2 3:17 False Start on the Jaguars (Dan Arnold), 5 yards · pre-snap +1% SF +0.7 pts
Q3 0:52 False Start on the Jaguars (Marvin Jones), 5 yards · pre-snap 0% SF +0.7 pts
Q4 12:53 Offensive Holding on the Jaguars, 10 yards, wiping out the play 0% SF +1.9 pts
Q4 11:07 Delay of Game on the Jaguars, 5 yards · pre-snap 0% SF +0.2 pts
Q4 3:17 Defensive Pass Interference on the 49ers (Jaquiski Tartt), 12 yards 0% JAX +1.8 pts

49ers penalties, every game · Jaguars penalties, every game · All teams, 2021

When it happened

Jaguars’ chance of winning

As low as 0% and as high as 59%. 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 Jaguars were ahead in it, below while the 49ers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 9:11 Defensive Holding on the Jaguars (Rayshawn Jenkins), 5 yardsJudgment calls · 7 flags in 2640 snaps before, position avg 1 per 420 +5% SF SF: Field goal
2 Q1 7:25 The 49ers converted 3rd & 123rd & 4th downs · 25% expected +11% SF SF: Field goal
3 Q1 4:35 The 49ers fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +7% SF SF: Field goal
4 Q1 3:46 Defensive Offside on the Jaguars (Dawuane Smoot), 5 yardsPre-snap flags · 7 flags in 1552 snaps before, position avg 1 per 266 +5% SF SF: Field goal
5 Q1 2:44 The 49ers were stopped on 3rd & 13rd & 4th downs · 67% expected +4% JAX SF: Field goal
6 Q1 1:59 R. Gould made 20-yard field goalKicks · 98% expected for him +13% JAX SF: Touchdown
7 Q2 11:24 The Jaguars fumbled and the 49ers recoveredFumble bounces · loose balls are close to 50/50 +4% SF JAX: Field goal
8 Q3 8:55 The 49ers converted 4th & 13rd & 4th downs · 67% expected +4% SF SF: 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.

  • Tre Herndon (JAX CB), out · 0.4 pts
  • Brandon Linder (JAX G), out (IR) · 0.4 pts
  • A.J. Cann (JAX G), out (IR) · 0.3 pts
  • Mike McGlinchey (SF T), out (IR) · 0.9 pts
  • Mohamed Sanu (SF WR), out (IR) · 0.4 pts
  • Javon Kinlaw (SF DT), out (IR) · 0.3 pts
  • Elijah Mitchell (SF RB), out · 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

49ers 92% · Jaguars 8%

Final margin
49ers by 20
Luck in points
10.5 for the 49ers
Luck-adjusted margin
49ers by 9.5
Replay with same day's form
49ers 91% · Jaguars 9% 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 11 2021 games · 49ers · Jaguars

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