luckadjusted

Week 2 2024 · September 15, 2024

49ers at Vikings, Week 2 2024: who deserved to win?

The Vikings beat the 49ers 23–17, but it was a coin flip: replayed with the way both teams played, the Vikings win 5 of 10. Luck ran their way: 3rd & 4th downs alone were worth 5.5 points to the Vikings.

Before kickoff the 49ers were 63% favorites. The biggest swing (Q2, 10:31 left): the 49ers were stopped on 4th & 2, worth 13 points of win probability to the Vikings.

Final

San Francisco 49ers 17
Minnesota Vikings 23

September 15, 2024 · U.S. Bank Stadium · Closing line: 49ers −4.5

Luck index +53 Vikings lucky · −53 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. 49ers win 5, Vikings win 5.

  1. 1 SF 33 MIN 13
  2. 2 SF 30 MIN 17
  3. 3 SF 24 MIN 14
  4. 4 SF 31 MIN 26
  5. 5 SF 26 MIN 24
  6. 6 SF 21 MIN 23
  7. 7 SF 26 MIN 31
  8. 8 SF 17 MIN 26
  9. 9 SF 24 MIN 38
  10. 10 SF 14 MIN 36

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 53% of them, Vikings 47%, counting the 6% still level after regulation as half each. The line is what actually happened: Vikings by 6.

Show as a table
Final margin in the replaysShare of replays
49ers by 17+11.5%
49ers by 9–1614.6%
49ers by 1–822.4%
Level after regulation5.9%
Vikings by 1–821.7%
Vikings by 9–1613.4%
Vikings by 17+10.5%

Where the luck was

Take the luck out

The final margin was Vikings by 6. Remove the luck, one kind at a time, and it becomes Vikings by 3.3.

Each row takes one kind of luck out of the margin. Color shows which team it helped. Luck shares are the fitted ones (how much of each component is luck).

The kicks

How likely each kicker was to make that kick (his own record, the distance and the weather), and what happened.

  • W. Reichard, 22 yds made · 99% expected
  • W. Reichard, 39 yds made · 90% expected
  • W. Reichard, 27 yds made · 98% expected
  • J. Moody, 31 yds made · 96% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Vikings’ chance of winning

As low as 50% 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 Vikings were ahead in it, below while the 49ers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 9:04 Offensive Holding on the 49ers (Deebo Samuel), 10 yards, wiping out the playJudgment calls · 12 flags in 3854 snaps before, position avg 1 per 409 +5% MIN MIN: Field goal
2 Q1 7:04 Blocked punt by the VikingsSpecial teams +11% MIN MIN: Field goal
3 Q2 13:33 The 49ers converted 4th & 33rd & 4th downs · 54% expected +13% SF SF: Turnover on downs
4 Q2 10:31 The 49ers were stopped on 4th & 23rd & 4th downs · 54% expected +13% MIN SF: Turnover on downs
5 Q2 0:32 The Vikings converted 3rd & 133rd & 4th downs · 22% expected +6% MIN MIN: Field goal
6 Q3 2:33 The 49ers were stopped on 3rd & 153rd & 4th downs · 22% expectedThe 49ers fumbled and the Vikings recoveredFumble bounces · loose balls are close to 50/50 +6% MIN SF: Touchdown
7 Q4 7:41 The Vikings converted 3rd & 83rd & 4th downs · 31% expected +5% MIN MIN: Field goal
8 Q4 1:57 The 49ers were stopped on 3rd & 13rd & 4th downs · 68% expected +8% MIN SF: Field goal

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.

  • T.J. Hockenson (MIN TE), out (IR) · 1.0 pts
  • Jordan Addison (MIN WR), out · 0.9 pts
  • Dalton Risner (MIN G), out (IR) · 0.3 pts
  • Christian McCaffrey (SF RB), out (IR) · 0.7 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

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 32% · Vikings 68%

Final margin
Vikings by 6
Luck in points
2.7 for the Vikings
Luck-adjusted margin
Vikings by 3.3
Replay with same day's form
49ers 53% · Vikings 47% 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 2 2024 games · 49ers · Vikings

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