luckadjusted

Week 1 2019 · September 8, 2019

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

49ers at Buccaneers, Week 1 2019: who deserved to win?

The 49ers beat the Buccaneers 31–17, but it was a coin flip: replayed with the way both teams played, the 49ers win 6 of 10. Luck ran their way: judgment calls alone were worth 2.1 points to the 49ers.

Before kickoff it was a pick’em. The biggest swing (Q2, 0:17 left): the 49ers were stopped on 3rd & 18, worth 25 points of win probability to the Buccaneers.

Final

San Francisco 49ers 31
Tampa Bay Buccaneers 17

September 8, 2019 · Raymond James Stadium · Closing line: Buccaneers −1

Luck index +41 49ers lucky · −41 Buccaneers

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 6, Buccaneers win 4.

  1. 1 SF 31 TB 7
  2. 2 SF 36 TB 20
  3. 3 SF 27 TB 17
  4. 4 SF 17 TB 9
  5. 5 SF 27 TB 23
  6. 6 SF 23 TB 21
  7. 7 SF 21 TB 23
  8. 8 SF 21 TB 27
  9. 9 SF 13 TB 24
  10. 10 SF 10 TB 28

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 59% of them, Buccaneers 41%, counting the 3% still level after regulation as half each. The line is what actually happened: 49ers by 14.

Show as a table
Final margin in the replaysShare of replays
49ers by 17+14.0%
49ers by 9–1616.9%
49ers by 1–826.8%
Level after regulation3.2%
Buccaneers by 1–819.5%
Buccaneers by 9–1613.2%
Buccaneers by 17+6.4%

Where the luck was

Take the luck out

The final margin was 49ers by 14. Remove the luck, one kind at a time, and it becomes 49ers by 16.2.

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. Gould, 29 yds made · 97% expected
  • R. Gould, 36 yds made · 91% expected
  • R. Gould, 57 yds missed · 58% expected
  • M. Gay, 31 yds made · 95% expected
  • R. Gould, 47 yds made · 74% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Buccaneers’ chance of winning

As low as 0% and as high as 63%. 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 Buccaneers were ahead in it, below while the 49ers were.
#WhenWhat happenedWin probability forNext drive
1 Q2 12:10 Offensive Holding on the Buccaneers, 10 yards, wiping out the playJudgment calls +16% SF SF: Opp touchdown
2 Q2 12:01 The Buccaneers were stopped on 3rd & 193rd & 4th downs · 16% expectedThe Buccaneers fumbled and the 49ers recoveredFumble bounces · loose balls are close to 50/50 +16% SF TB: Opp touchdown
3 Q2 8:47 Return touchdown by the BuccaneersSpecial teams +22% TB TB: Opp touchdown
4 Q2 3:46 Illegal Formation on the 49ers, 5 yards, wiping out the playPre-snap flags +16% TB TB: Turnover
5 Q2 0:17 The 49ers were stopped on 3rd & 183rd & 4th downs · 17% expectedThe 49ers fumbled and the Buccaneers recoveredFumble bounces · loose balls are close to 50/50 +25% TB SF: Touchdown
6 Q3 11:53 Return touchdown by the 49ersSpecial teams +15% SF SF: Opp touchdown
7 Q4 5:30 The Buccaneers were stopped on 3rd & 73rd & 4th downs · 24% expected +15% SF TB: Field goal
8 Q4 2:10 Return touchdown by the 49ersSpecial teams +17% SF SF: Opp touchdown

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.

  • Justin Evans (TB SS), out · 0.1 pts
  • Jimmie Ward (SF CB), out · 0.5 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 95% · Buccaneers 5%

Final margin
49ers by 14
Luck in points
2.2 for the Buccaneers
Luck-adjusted margin
49ers by 16.2
Replay with same day's form
49ers 59% · Buccaneers 41% 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 1 2019 games · 49ers · Buccaneers

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