luckadjusted

Week 2 2019 · September 15, 2019

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

49ers at Bengals, Week 2 2019: who deserved to win?

The 49ers beat the Bengals 41–17, and it was no fluke: replayed with the way both teams actually played, the 49ers win 10 of 10. The Bengals had the bounces: 3rd & 4th downs alone were worth 1.6 points to the Bengals.

An off day for the Bengals: their offense and defense both played far below their usual level. In a fresh game against the 49ers they would win 38% of the time; with this day’s form, 1%. The numbers

Before kickoff it was a pick’em. The biggest swing (Q2, 5:01 left): Offensive Holding on the 49ers, 10 yards, wiping out the play, worth 10 points of win probability to the Bengals.

Final

San Francisco 49ers 41
Cincinnati Bengals 17

September 15, 2019 · Paul Brown Stadium · Closing line: Bengals −1

Luck index +1 49ers about even · −1 Bengals

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, Bengals win 0.

  1. 1 SF 47 CIN 3
  2. 2 SF 42 CIN 7
  3. 3 SF 40 CIN 10
  4. 4 SF 40 CIN 14
  5. 5 SF 31 CIN 9
  6. 6 SF 33 CIN 13
  7. 7 SF 23 CIN 7
  8. 8 SF 35 CIN 23
  9. 9 SF 31 CIN 24
  10. 10 SF 34 CIN 31

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.

An off day for the Bengals

Their offense and defense both played far below their usual level. In a fresh game against the 49ers they would win 38% of the time; with this day’s form, 1%.

37 points apart for the Bengals: the gap is how differently this game went from what the two teams usually are.

UnitThis gameUsual levelBetter or worse than usual
49ers offenseEPA per play gained +0.64 +0.09 better by 0.55
49ers defenseEPA per play allowed −0.01 +0.09 better by 0.11
Bengals offenseEPA per play gained −0.01 +0.09 worse by 0.11
Bengals defenseEPA per play allowed +0.64 +0.16 worse by 0.48

EPA (expected points added) per play on competitive snaps, turnovers left out because they are valued as luck. Usual level: the team’s earlier games this season plus half of last season, pulled toward the league average. One team’s defense and the other team’s offense are the same snaps, so one game can’t fully say whose day it was; it shows how far this one was from both teams’ norms.

How 4,000 replays ended

49ers win 99% of them, Bengals 1%. The line is what actually happened: 49ers by 24.

Show as a table
Final margin in the replaysShare of replays
49ers by 17+80.7%
49ers by 9–1613.3%
49ers by 1–84.2%
Level after regulation0.5%
Bengals by 1–81.0%
Bengals by 9–160.2%
Bengals by 17+0.1%

Where the luck was

Take the luck out

The final margin was 49ers by 24. Remove the luck, one kind at a time, and it becomes 49ers by 25.2.

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.

  • R. Bullock, 52 yds missed · 67% expected
  • R. Bullock, 37 yds made · 91% expected
  • R. Gould, 33 yds made · 94% expected
  • R. Gould, 38 yds made · 90% expected
  • R. Gould, 39 yds missed · 89% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Bengals’ chance of winning

As low as 0% and as high as 55%. 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 Bengals were ahead in it, below while the 49ers were.
#WhenWhat happenedWin probability forNext drive
1 Q1 14:17 The Bengals fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +6% CIN CIN: Punt
2 Q1 11:50 The 49ers converted 3rd & 23rd & 4th downs · 64% expected +9% SF SF: Touchdown
3 Q1 0:56 Offensive Holding on the Bengals, 10 yards, wiping out the playJudgment calls +7% SF SF: Turnover
4 Q2 14:04 Offensive Holding on the Bengals, 10 yards, wiping out the playJudgment calls +7% SF SF: Touchdown
5 Q2 13:01 The Bengals were stopped on 3rd & 153rd & 4th downs · 19% expectedIllegal Forward Pass on the Bengals (Andy Dalton), 5 yardsJudgment calls · 0 flags in 75 snaps before, position avg 1 per 751 +7% SF CIN: Missed field goal
6 Q2 11:26 The 49ers converted 3rd & 13rd & 4th downs · 77% expected +6% SF SF: Touchdown
7 Q2 8:11 The Bengals converted 3rd & 93rd & 4th downs · 27% expected +6% CIN CIN: Field goal
8 Q2 5:01 Offensive Holding on the 49ers, 10 yards, wiping out the playJudgment calls +10% CIN CIN: Turnover

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.

  • Cordy Glenn (CIN T), out · 0.9 pts
  • Jimmie Ward (SF CB), out · 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 100% · Bengals 0%

Final margin
49ers by 24
Luck in points
1.2 for the Bengals
Luck-adjusted margin
49ers by 25.2
Replay with same day's form
49ers 99% · Bengals 1% 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 2 2019 games · 49ers · Bengals

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