luckadjusted

Week 4 2024 · September 29, 2024

Patriots at 49ers, Week 4 2024: who deserved to win?

The 49ers beat the Patriots 30–13, and it was no fluke: replayed with the way both teams actually played, the 49ers win 10 of 10.

Before kickoff the 49ers were 78% favorites. The biggest swing (Q2, 14:15 left): Return touchdown by the 49ers, worth 29 points of win probability to the 49ers.

Final

New England Patriots 13
San Francisco 49ers 30

September 29, 2024 · Levi's Stadium · Closing line: 49ers −10.5

Luck index +1 49ers about even · −1 Patriots

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. Patriots win 0, 49ers win 10.

  1. 1 NE 15 SF 19
  2. 2 NE 7 SF 17
  3. 3 NE 13 SF 27
  4. 4 NE 14 SF 31
  5. 5 NE 7 SF 27
  6. 6 NE 13 SF 35
  7. 7 NE 10 SF 35
  8. 8 NE 6 SF 34
  9. 9 NE 0 SF 33
  10. 10 NE 0 SF 41

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

Patriots win 1% of them, 49ers 99%. The line is what actually happened: 49ers by 17.

Show as a table
Final margin in the replaysShare of replays
Patriots by 17+0.0%
Patriots by 9–160.1%
Patriots by 1–80.5%
Level after regulation0.2%
49ers by 1–82.1%
49ers by 9–168.3%
49ers by 17+88.8%

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 +0.8 points to the 49ers: the final margin was 49ers by 17, without the luck 49ers by 16.1. 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.

  • J. Moody, 22 yds made · 99% expected
  • J. Moody, 26 yds made · 98% expected
  • J. Slye, 63 yds made · 51% expected
  • J. Slye, 54 yds made · 64% expected
  • J. Moody, 41 yds made · 86% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Patriots 3 for 20 yards, 49ers 6 for 43 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 10:20 Delay of Game on the Patriots, 5 yards · pre-snap +3% SF +0.6 pts
Q2 10:00 Defensive Too Many Men on Field on the 49ers, 5 yards · pre-snap 0% SF +0.8 pts
Q2 5:18 Offensive Holding on the 49ers (George Kittle), 10 yards 0% NE +1.0 pts
Q2 3:37 Illegal Shift on the 49ers, 5 yards, wiping out the play · pre-snap +2% NE +2.9 pts
Q3 6:30 False Start on the 49ers, 5 yards · pre-snap 0% NE +0.7 pts
Q3 3:36 Illegal Block Above the Waist on the Patriots (Tyquan Thornton), 10 yards +1% SF +1.2 pts
Q3 0:05 Defensive Pass Interference on the 49ers (Deommodore Lenoir), 13 yards 0% NE +1.1 pts
Q4 12:38 Illegal Shift on the 49ers, 5 yards, wiping out the play · pre-snap +1% NE +2.1 pts
Q4 6:56 Defensive Too Many Men on Field on the Patriots, 5 yards · pre-snap 0% SF +0.7 pts

Patriots penalties, every game · 49ers penalties, every game · All teams, 2024

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 Patriots were.
#WhenWhat happenedWin probability forNext drive
1 Q1 12:25 The Patriots converted 3rd & 73rd & 4th downs · 29% expected +6% NE NE: Punt
2 Q1 10:24 The Patriots were stopped on 3rd & 33rd & 4th downs · 47% expected +4% SF NE: Punt
3 Q1 4:47 J. Jennings dropped a catchable passDrops · 1 drops on 93 catchable balls before this +4% NE SF: Field goal
4 Q1 4:43 The 49ers converted 3rd & 93rd & 4th downs · 30% expected +4% SF SF: Field goal
5 Q1 2:26 The Patriots fumbled and the 49ers recoveredFumble bounces · loose balls are close to 50/50 +6% SF NE: Opp touchdown
6 Q2 14:15 The Patriots were stopped on 3rd & 53rd & 4th downs · 36% expectedThe Patriots threw an interception-worthy pass, and it was pickedInterceptions · 51% expected to stay out of the defense's handsReturn touchdown by the 49ersSpecial teams +29% SF NE: Turnover on downs
7 Q2 8:11 The Patriots were stopped on 4th & 13rd & 4th downs · 69% expected +4% SF NE: Punt
8 Q3 12:11 The Patriots converted 4th & 13rd & 4th downs · 61% expected +4% NE NE: 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.

  • Christian McCaffrey (SF RB), out (IR) · 0.7 pts
  • Javon Hargrave (SF DT), out (IR) · 0.4 pts
  • Dre Greenlaw (SF LB), out (IR) · 0.3 pts
  • Jon Feliciano (SF C), out (IR) · 0.3 pts
  • Ambry Thomas (SF CB), out (IR) · 0.3 pts
  • Ja'Whaun Bentley (NE LB), out (IR) · 0.5 pts
  • Vederian Lowe (NE T), out · 0.4 pts
  • Christian Barmore (NE DT), out (IR) · 0.2 pts
  • Cole Strange (NE G), out (IR) · 0.2 pts
  • Anfernee Jennings (NE LB), 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

Patriots 1% · 49ers 99%

Final margin
49ers by 17
Luck in points
0.8 for the 49ers
Luck-adjusted margin
49ers by 16.2
Replay with same day's form
Patriots 1% · 49ers 99% 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 4 2024 games · Patriots · 49ers

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