luckadjusted

Divisional round 2019 · January 11, 2020

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

Vikings at 49ers, Divisional round 2019: who deserved to win?

The 49ers beat the Vikings 27–10, and it was no fluke: replayed with the way both teams actually played, the 49ers win 10 of 10. The Vikings had the bounces: fumble bounces alone were worth 4.7 points to the Vikings.

Before kickoff the 49ers were 70% favorites. The biggest swing (Q1, 5:30 left): the Vikings converted 3rd & 2, worth 13 points of win probability to the Vikings.

Final

Minnesota Vikings 10
San Francisco 49ers 27

January 11, 2020 · Levi's Stadium · Closing line: 49ers −7

Luck index +4 49ers about even · −4 Vikings

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. Vikings win 0, 49ers win 10.

  1. 1 MIN 21 SF 24
  2. 2 MIN 20 SF 26
  3. 3 MIN 13 SF 22
  4. 4 MIN 14 SF 25
  5. 5 MIN 10 SF 24
  6. 6 MIN 10 SF 27
  7. 7 MIN 10 SF 30
  8. 8 MIN 3 SF 27
  9. 9 MIN 3 SF 30
  10. 10 MIN 10 SF 44

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

Vikings win 4% of them, 49ers 96%, counting the 1% still level after regulation as half each. The line is what actually happened: 49ers by 17.

Show as a table
Final margin in the replaysShare of replays
Vikings by 17+0.1%
Vikings by 9–160.6%
Vikings by 1–83.4%
Level after regulation0.6%
49ers by 1–88.0%
49ers by 9–1618.9%
49ers by 17+68.3%

Where the luck was

Take the luck out

The final margin was 49ers by 17. Remove the luck, one kind at a time, and it becomes 49ers by 19.9.

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.

  • D. Bailey, 39 yds made · 88% expected
  • R. Gould, 35 yds made · 91% expected
  • R. Gould, 21 yds made · 98% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

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 Vikings were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:56 The Vikings were stopped on 3rd & 83rd & 4th downs · 29% expected +4% SF MIN: Punt
2 Q1 5:30 The Vikings converted 3rd & 23rd & 4th downs · 58% expected +13% MIN MIN: Touchdown
3 Q1 2:07 The 49ers converted 3rd & 103rd & 4th downs · 30% expected +8% SF SF: Punt
4 Q2 15:00 The Vikings fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +7% MIN MIN: Punt
5 Q2 11:39 The 49ers converted 3rd & 123rd & 4th downs · 27% expected +8% SF SF: Touchdown
6 Q3 15:00 Unnecessary Roughness on the Vikings, 15 yardsJudgment calls +4% SF SF: Field goal
7 Q3 14:32 The 49ers converted 3rd & 53rd & 4th downs · 43% expected +8% SF SF: Field goal
8 Q3 10:54 The 49ers were stopped on 3rd & 23rd & 4th downs · 63% expected +4% 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.

  • Weston Richburg (SF C), out (IR) · 0.6 pts
  • Aviante Collins (MIN T), out · 0.3 pts
  • Mackensie Alexander (MIN 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

Vikings 0% · 49ers 100%

Final margin
49ers by 17
Luck in points
2.9 for the Vikings
Luck-adjusted margin
49ers by 19.9
Replay with same day's form
Vikings 4% · 49ers 96% 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 Divisional round 2019 games · Vikings · 49ers

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