luckadjusted

Week 13 2023 · December 3, 2023

49ers at Eagles, Week 13 2023: who deserved to win?

The 49ers beat the Eagles 42–19, and it was no fluke: replayed with the way both teams actually played, the 49ers win 10 of 10.

Before kickoff the 49ers were 59% favorites. The biggest swing (Q1, 14:11 left): the Eagles converted 3rd & 9, worth 13 points of win probability to the Eagles.

Final

San Francisco 49ers 42
Philadelphia Eagles 19

December 3, 2023 · Lincoln Financial Field · Closing line: 49ers −3

Luck index +3 49ers about even · −3 Eagles

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 10, Eagles win 0.

  1. 1 SF 40 PHI 7
  2. 2 SF 45 PHI 17
  3. 3 SF 38 PHI 14
  4. 4 SF 27 PHI 7
  5. 5 SF 30 PHI 13
  6. 6 SF 17 PHI 3
  7. 7 SF 14 PHI 3
  8. 8 SF 24 PHI 16
  9. 9 SF 27 PHI 21
  10. 10 SF 17 PHI 14

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 97% of them, Eagles 3%. The line is what actually happened: 49ers by 23.

Show as a table
Final margin in the replaysShare of replays
49ers by 17+67.0%
49ers by 9–1621.9%
49ers by 1–88.2%
Level after regulation0.4%
Eagles by 1–82.0%
Eagles by 9–160.4%
Eagles by 17+0.1%

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 +4.0 points to the Eagles: the final margin was 49ers by 23, without the luck 49ers by 27. 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. Elliott, 26 yds made · 95% expected
  • J. Elliott, 39 yds made · 75% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: 49ers 5 for 47 yards, Eagles 7 for 47 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
Q2 15:00 False Start on the Eagles (Jalen Hurts), 5 yards · pre-snap +3% SF +0.8 pts
Q2 13:25 False Start on the 49ers, 5 yards · pre-snap +2% PHI +0.7 pts
Q2 7:19 Defensive Offside on the Eagles (Josh Sweat), 2 yards · pre-snap +1% SF +0.5 pts
Q2 0:57 Defensive Offside on the Eagles (Josh Sweat), 5 yards, wiping out the play · pre-snap +1% PHI +0.1 pts
Q3 11:41 Face Mask on the 49ers, 15 yards +3% PHI +1.4 pts
Q3 10:12 Offensive Pass Interference on the Eagles (DeVonta Smith), 10 yards, wiping out the play +2% SF +1.8 pts
Q3 9:27 Disqualification on the 49ers (Dre Greenlaw), 12 yards +3% PHI +1.0 pts
Q3 3:54 Unnecessary Roughness on the Eagles (Jalen Carter), 15 yards 0% SF 0.0 pts
Q4 5:48 Defensive Pass Interference on the 49ers (Deommodore Lenoir), 11 yards 0% PHI +2.0 pts
Q4 5:48 False Start on the Eagles, 5 yards · pre-snap 0% SF +0.6 pts
Q4 5:32 False Start on the 49ers, 4 yards · pre-snap 0% PHI +0.5 pts
Q4 3:01 False Start on the Eagles, 5 yards · pre-snap 0% SF +0.9 pts

49ers penalties, every game · Eagles penalties, every game · All teams, 2023

When it happened

Eagles’ chance of winning

As low as 0% and as high as 75%. 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 Eagles were ahead in it, below while the 49ers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 14:11 The Eagles converted 3rd & 93rd & 4th downs · 32% expected +13% PHI PHI: Field goal
2 Q1 8:49 The Eagles fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +6% PHI PHI: Field goal
3 Q1 2:05 J. Elliott made 39-yard field goalKicks · 75% expected for him +10% PHI PHI: Punt
4 Q2 7:15 The 49ers converted 3rd & 23rd & 4th downs · 57% expected +7% SF SF: Touchdown
5 Q2 6:18 The Eagles converted 3rd & 193rd & 4th downs · 21% expected +8% PHI PHI: Punt
6 Q3 14:23 The 49ers converted 3rd & 53rd & 4th downs · 45% expected +6% SF SF: Touchdown
7 Q3 12:29 The 49ers converted 3rd & 33rd & 4th downs · 57% expected +6% SF SF: Touchdown
8 Q3 8:01 The Eagles converted 3rd & 123rd & 4th downs · 28% expected +5% PHI PHI: 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.

  • Dallas Goedert (PHI TE), out · 1.0 pts
  • Zach Cunningham (PHI LB), out · 0.3 pts
  • Nakobe Dean (PHI LB), out (IR) · 0.1 pts
  • Talanoa Hufanga (SF SS), out (IR) · 0.6 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 100% · Eagles 0%

Final margin
49ers by 23
Luck in points
4.0 for the Eagles
Luck-adjusted margin
49ers by 27.0
Replay with same day's form
49ers 97% · Eagles 3% 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 2023 games · 49ers · Eagles

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