luckadjusted

Week 14 2019 · December 8, 2019

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

49ers at Saints, Week 14 2019: who deserved to win?

The 49ers beat the Saints 48–46 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 (Q4, 0:39 left): Face Mask on the Saints (Marcus Williams), 14 yards, worth 18 points of win probability to the 49ers. The biggest single swing (Q4, 0:02 left): R. Gould made 30-yard field goal.

Final

San Francisco 49ers 48
New Orleans Saints 46

December 8, 2019 · Mercedes-Benz Superdome · Closing line: Saints −1

Luck index +33 49ers lucky · −33 Saints

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 7, Saints win 3.

  1. 1 SF 40 NO 12
  2. 2 SF 46 NO 28
  3. 3 SF 41 NO 27
  4. 4 SF 37 NO 26
  5. 5 SF 42 NO 34
  6. 6 SF 45 NO 40
  7. 7 SF 41 NO 38
  8. 8 SF 33 NO 36
  9. 9 SF 30 NO 37
  10. 10 SF 27 NO 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

49ers win 67% of them, Saints 33%, counting the 3% still level after regulation as half each. The line is what actually happened: 49ers by 2.

Show as a table
Final margin in the replaysShare of replays
49ers by 17+24.6%
49ers by 9–1619.5%
49ers by 1–822.6%
Level after regulation3.4%
Saints by 1–815.6%
Saints by 9–168.3%
Saints by 17+6.0%

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 0.0 points to the Saints: the final margin was 49ers by 2, without the luck 49ers by 2. 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.

  • W. Lutz, 55 yds made · 66% expected
  • W. Lutz, 48 yds made · 78% expected
  • R. Gould, 41 yds made · 86% expected
  • R. Gould, 30 yds made · 95% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: 49ers 10 for 67 yards, Saints 5 for 50 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 10:54 False Start on the 49ers, 5 yards · pre-snap +2% NO +0.6 pts
Q1 4:58 Unnecessary Roughness on the 49ers (Ahkello Witherspoon), 1 yard 0% NO +0.1 pts
Q1 4:15 False Start on the 49ers, 5 yards · pre-snap +1% NO +0.8 pts
Q2 4:25 Offensive Holding on the 49ers (D.J. Reed), 10 yards +3% NO +1.0 pts
Q2 2:00 Illegal Block Above the Waist on the 49ers (Emmanuel Sanders), 10 yards +4% NO +0.8 pts
Q2 0:45 False Start on the 49ers, 5 yards · pre-snap +2% NO +0.9 pts
Q3 3:16 Offensive Holding on the 49ers (Marcell Harris), 10 yards, wiping out the play +5% NO +1.5 pts
Q3 1:42 Offensive Pass Interference on the Saints (Michael Thomas), 10 yards, wiping out the play +10% SF +1.6 pts
Q3 0:17 Illegal Block Above the Waist on the 49ers (Deebo Samuel), 10 yards +4% NO +0.7 pts
Q4 14:19 Defensive Holding on the Saints (C.J. Gardner-Johnson), 5 yards +7% SF +1.5 pts
Q4 9:44 Unnecessary Roughness on the Saints (C.J. Gardner-Johnson), 6 yards +3% SF +0.6 pts
Q4 8:59 Leverage on the Saints (Mario Edwards), 15 yards +5% SF +1.5 pts
Q4 7:53 Defensive Holding on the 49ers (Richard Sherman), 5 yards +2% NO +1.3 pts
Q4 1:05 Defensive Pass Interference on the 49ers, 6 yards +7% NO +1.1 pts
Q4 0:39 Face Mask on the Saints (Marcus Williams), 14 yards +18% SF +1.8 pts

49ers penalties, every game · Saints penalties, every game · All teams, 2019

When it happened

Saints’ chance of winning

As low as 0% and as high as 86%. 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 Saints were ahead in it, below while the 49ers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 11:42 The Saints converted 3rd & 103rd & 4th downs · 27% expected +12% NO NO: Touchdown
2 Q1 8:31 The 49ers converted 3rd & 63rd & 4th downs · 32% expected +9% SF SF: Touchdown
3 Q3 10:34 The Saints fumbled and the 49ers recoveredFumble bounces · loose balls are close to 50/50 +12% SF NO: Field goal
4 Q3 1:42 Offensive Pass Interference on the Saints (Michael Thomas), 10 yards, wiping out the playJudgment calls · 5 flags in 724 snaps before, position avg 1 per 331 +10% SF SF: Touchdown
5 Q3 1:03 The Saints were stopped on 4th & 183rd & 4th downs · 18% expected +10% SF NO: Touchdown
6 Q4 0:53 The Saints’ two-point try failed3rd & 4th downs · 47% expected +10% SF –
7 Q4 0:39 The game turned hereFace Mask on the Saints (Marcus Williams), 14 yardsJudgment calls · 1 flag in 825 snaps before, position avg 1 per 465 +18% SF SF: Field goal
8 Q4 0:02 R. Gould made 30-yard field goalKicks · 95% expected for him +46% SF –

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.

  • Andrus Peat (NO G), out · 0.4 pts
  • A.J. Klein (NO LB), out · 0.2 pts
  • Jaquiski Tartt (SF SS), out · 0.4 pts
  • Kwon Alexander (SF LB), 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 59% · Saints 41%

Final margin
49ers by 2
Luck in points
none
Luck-adjusted margin
49ers by 2.0
Replay with same day's form
49ers 67% · Saints 33% 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 14 2019 games · 49ers · Saints

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