luckadjusted

Week 13 2022 · December 4, 2022

Dolphins at 49ers, Week 13 2022: who deserved to win?

The 49ers beat the Dolphins 33–17 and were the better team on the day: replayed with the same form, they win 8 of 10.

Before kickoff the 49ers were 63% favorites. The biggest swing (Q4, 6:03 left): the Dolphins were stopped on 4th & 2, worth 9 points of win probability to the 49ers.

Final

Miami Dolphins 17
San Francisco 49ers 33

December 4, 2022 · Levi's Stadium · Closing line: 49ers −4.5

Luck index +21 49ers about even · −21 Dolphins

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. Dolphins win 2, 49ers win 8.

  1. 1 MIA 31 SF 17
  2. 2 MIA 28 SF 24
  3. 3 MIA 11 SF 13
  4. 4 MIA 24 SF 29
  5. 5 MIA 35 SF 42
  6. 6 MIA 23 SF 33
  7. 7 MIA 10 SF 24
  8. 8 MIA 10 SF 29
  9. 9 MIA 6 SF 30
  10. 10 MIA 28 SF 60

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

Dolphins win 21% of them, 49ers 79%, counting the 2% still level after regulation as half each. The line is what actually happened: 49ers by 16.

Show as a table
Final margin in the replaysShare of replays
Dolphins by 17+3.0%
Dolphins by 9–165.7%
Dolphins by 1–811.3%
Level after regulation1.7%
49ers by 1–821.8%
49ers by 9–1620.5%
49ers by 17+35.9%

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 +11.5 points to the 49ers: the final margin was 49ers by 16, without the luck 49ers by 4.5. 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, 47 yds made · 73% expected
  • J. Sanders, 43 yds made · 80% expected
  • R. Gould, 43 yds made · 80% expected
  • R. Gould, 36 yds made · 90% expected
  • R. Gould, 48 yds made · 71% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Dolphins 8 for 68 yards, 49ers 4 for 45 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 6:37 Defensive Pass Interference on the Dolphins, 14 yards +6% SF +2.0 pts
Q1 4:01 Player Out of Bounds on Kick on the Dolphins, 5 yards +1% SF +0.5 pts
Q1 3:11 Tripping on the Dolphins (Melvin Ingram), 10 yards +3% SF +0.7 pts
Q2 2:14 Ineligible Downfield Pass on the 49ers, 5 yards +3% MIA +0.6 pts
Q2 0:41 Defensive Pass Interference on the Dolphins (Xavien Howard), 4 yards 0% SF +0.3 pts
Q3 11:22 Unsportsmanlike Conduct on the 49ers (Tarvarius Moore), 15 yards +2% MIA +1.6 pts
Q3 11:12 Roughing the Passer on the 49ers (Nick Bosa), 15 yards +5% MIA +2.1 pts
Q3 10:47 False Start on the Dolphins, 5 yards · pre-snap +3% SF +0.8 pts
Q3 10:33 Offensive Holding on the Dolphins, 10 yards, wiping out the play +8% SF +2.4 pts
Q3 2:57 Unsportsmanlike Conduct on the Dolphins (Bradley Chubb), 15 yards +4% SF +0.8 pts
Q3 0:12 False Start on the Dolphins (Trent Sherfield), 5 yards · pre-snap +1% SF +0.5 pts
Q4 2:55 Offensive Holding on the 49ers (George Kittle), 10 yards, wiping out the play +5% MIA +2.2 pts

Dolphins penalties, every game · 49ers penalties, every game · All teams, 2022

When it happened

49ers’ chance of winning

As low as 32% 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 49ers were ahead in it, below while the Dolphins were.
#WhenWhat happenedWin probability forNext drive
1 Q1 14:04 The 49ers converted 3rd & 73rd & 4th downs · 34% expected +7% SF SF: Field goal
2 Q2 11:02 The Dolphins were stopped on 3rd & 13rd & 4th downs · 73% expected +8% SF MIA: Field goal
3 Q2 3:40 The Dolphins were stopped on 3rd & 83rd & 4th downs · 30% expected +7% SF MIA: Punt
4 Q3 10:33 Offensive Holding on the Dolphins, 10 yards, wiping out the playJudgment calls +8% SF SF: Field goal
5 Q3 2:57 R. Gould made 43-yard field goalKicks · 80% expected for himUnsportsmanlike Conduct on the Dolphins (Bradley Chubb), 15 yardsJudgment calls · 12 flags in 1854 snaps before, position avg 1 per 422 +7% SF SF: Field goal
6 Q4 9:59 The Dolphins converted 4th & 13rd & 4th downs · 72% expected +7% MIA MIA: Turnover on downs
7 Q4 6:03 The Dolphins were stopped on 4th & 23rd & 4th downs · 58% expected +9% SF MIA: Opp touchdown
8 Q4 2:03 The Dolphins fumbled and the 49ers recoveredFumble bounces · loose balls are close to 50/50Return touchdown by the 49ersSpecial teams +7% SF MIA: Turnover

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.

  • Emmanuel Moseley (SF CB), out (IR) · 0.6 pts
  • Spencer Burford (SF G), out · 0.2 pts
  • Liam Eichenberg (MIA T), out (IR) · 1.1 pts
  • Terron Armstead (MIA T), out · 1.0 pts
  • Nik Needham (MIA CB), out (IR) · 0.5 pts
  • Emmanuel Ogbah (MIA DE), out (IR) · 0.5 pts
  • Brandon Jones (MIA SS), out (IR) · 0.3 pts
  • Noah Igbinoghene (MIA CB), out · 0.2 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

Dolphins 17% · 49ers 83%

Final margin
49ers by 16
Luck in points
11.5 for the 49ers
Luck-adjusted margin
49ers by 4.5
Replay with same day's form
Dolphins 21% · 49ers 79% 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; injuries from snap counts and injury reports.

Methodology and validation · All Week 13 2022 games · Dolphins · 49ers

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