luckadjusted

Week 15 2019 · December 15, 2019

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

Vikings at Chargers, Week 15 2019: who deserved to win?

The Vikings beat the Chargers 39–10 and were the better team on the day: replayed with the same form, they win 7 of 10.

Before kickoff it was a pick’em. The game turned on a luck play (Q2, 0:23 left): Return touchdown by the Vikings, worth 61 points of win probability to the Vikings.

Final

Minnesota Vikings 39
Los Angeles Chargers 10

December 15, 2019 · StubHub Center · Closing line: Vikings −1

Luck index +26 Vikings lucky · −26 Chargers

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 7, Chargers win 3.

  1. 1 MIN 47 LAC 20
  2. 2 MIN 29 LAC 10
  3. 3 MIN 21 LAC 7
  4. 4 MIN 30 LAC 19
  5. 5 MIN 28 LAC 21
  6. 6 MIN 43 LAC 38
  7. 7 MIN 29 LAC 27
  8. 8 MIN 33 LAC 36
  9. 9 MIN 12 LAC 20
  10. 10 MIN 15 LAC 30

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 74% of them, Chargers 26%, counting the 4% still level after regulation as half each. The line is what actually happened: Vikings by 29.

Show as a table
Final margin in the replaysShare of replays
Vikings by 17+25.6%
Vikings by 9–1622.1%
Vikings by 1–822.9%
Level after regulation3.5%
Chargers by 1–814.8%
Chargers by 9–167.0%
Chargers by 17+4.1%

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 +11.0 points to the Vikings: the final margin was Vikings by 29, without the luck Vikings by 18. 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.

  • M. Badgley, 41 yds made · 83% expected
  • D. Bailey, 26 yds made · 98% expected
  • D. Bailey, 44 yds made · 78% expected
  • D. Bailey, 38 yds made · 88% expected
  • D. Bailey, 27 yds made · 97% expected
  • Extra point missed · 93% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Vikings 5 for 41 yards, Chargers 5 for 48 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 9:23 Defensive Pass Interference on the Chargers, 15 yards +8% MIN +2.7 pts
Q2 8:42 False Start on the Vikings (Stefon Diggs), 5 yards · pre-snap +3% LAC +0.6 pts
Q2 6:13 Defensive Holding on the Chargers, 5 yards +2% MIN +0.3 pts
Q2 3:41 Offensive Holding on the Chargers (Hunter Henry), 10 yards, wiping out the play +6% MIN +1.2 pts
Q3 13:41 False Start on the Vikings, 5 yards · pre-snap +4% LAC +0.8 pts
Q3 11:24 Intentional Grounding on the Chargers (Philip Rivers), 13 yards +2% MIN +1.0 pts
Q4 15:00 False Start on the Chargers, 5 yards · pre-snap +1% MIN +0.1 pts
Q4 12:22 Offensive Holding on the Vikings (Tyler Conklin), 11 yards, wiping out the play +1% LAC +2.0 pts
Q4 4:57 Offensive Holding on the Vikings (Laquon Treadwell), 10 yards 0% LAC +0.9 pts
Q4 4:49 Offensive Holding on the Vikings (Laquon Treadwell), 10 yards 0% LAC +0.9 pts

Vikings penalties, every game · Chargers penalties, every game · All teams, 2019

When it happened

Chargers’ chance of winning

As low as 0% and as high as 66%. 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 Chargers were ahead in it, below while the Vikings were.
#WhenWhat happenedWin probability forNext drive
1 Q1 9:23 Defensive Pass Interference on the Chargers, 15 yardsJudgment calls +8% MIN MIN: Touchdown
2 Q1 6:54 The Chargers converted 3rd & 123rd & 4th downs · 21% expected +11% LAC LAC: Field goal
3 Q1 1:34 The Chargers fumbled and the Vikings recoveredFumble bounces · loose balls are close to 50/50 +8% MIN LAC: Touchdown
4 Q2 11:20 The Chargers converted 3rd & 83rd & 4th downs · 27% expected +9% LAC LAC: Touchdown
5 Q2 8:46 The Chargers converted 3rd & 23rd & 4th downs · 47% expected +9% LAC LAC: Touchdown
6 Q2 6:55 The Vikings converted 3rd & 73rd & 4th downs · 34% expected +9% MIN MIN: Field goal
7 Q2 2:06 The Chargers were stopped on 3rd & 173rd & 4th downs · 17% expected +13% MIN LAC: Opp touchdown
8 Q2 0:23 The game turned hereThe Chargers fumbled and the Vikings recoveredFumble bounces · loose balls are close to 50/50Return touchdown by the VikingsSpecial teams +61% MIN LAC: End of half

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.

  • Roderic Teamer (LAC CB), out · 0.6 pts
  • Desmond King (LAC CB), out · 0.5 pts
  • Forrest Lamp (LAC G), out (IR) · 0.1 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 100% · Chargers 0%

Final margin
Vikings by 29
Luck in points
11.0 for the Vikings
Luck-adjusted margin
Vikings by 18.0
Replay with same day's form
Vikings 74% · Chargers 26% 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 Week 15 2019 games · Vikings · Chargers

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