luckadjusted

Week 16 2021 · December 23, 2021

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

49ers at Titans, Week 16 2021: who deserved to win?

The Titans beat the 49ers 20–17, but the 49ers played well enough to win it: they take 7 of 10 replays with the same day's form. Luck ran their way: 3rd & 4th downs alone were worth 4.0 points to the Titans.

Before kickoff the 49ers were 60% favorites. The biggest swing (Q4, 0:09 left): R. Bullock made 44-yard field goal, worth 18 points of win probability to the Titans.

Final

San Francisco 49ers 17
Tennessee Titans 20

December 23, 2021 · Nissan Stadium · Closing line: 49ers −3.5

Luck index +67 Titans very lucky · −67 49ers

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, Titans win 3.

  1. 1 SF 41 TEN 17
  2. 2 SF 30 TEN 13
  3. 3 SF 26 TEN 13
  4. 4 SF 27 TEN 17
  5. 5 SF 27 TEN 20
  6. 6 SF 12 TEN 7
  7. 7 SF 22 TEN 20
  8. 8 SF 6 TEN 8
  9. 9 SF 19 TEN 26
  10. 10 SF 10 TEN 26

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, Titans 33%, counting the 2% still level after regulation as half each. The line is what actually happened: Titans by 3.

Show as a table
Final margin in the replaysShare of replays
49ers by 17+17.3%
49ers by 9–1620.7%
49ers by 1–827.8%
Level after regulation2.4%
Titans by 1–819.6%
Titans by 9–169.0%
Titans by 17+3.4%

Where the luck was

Take the luck out

The final margin was Titans by 3. Remove the luck, one kind at a time, and it becomes Titans by 7.6.

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, 48 yds made · 71% expected
  • R. Bullock, 38 yds made · 89% expected
  • R. Bullock, 44 yds made · 81% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Titans’ chance of winning

As low as 19% and as high as 100%. 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 Titans were ahead in it, below while the 49ers were.
#WhenWhat happenedWin probability forNext drive
1 Q2 1:55 Offensive Holding on the Titans (Geoff Swaim), 10 yards, wiping out the playJudgment calls · 7 flags in 1494 snaps before, position avg 1 per 269 +15% SF SF: End of half
2 Q3 14:15 The Titans converted 3rd & 153rd & 4th downs · 20% expected +8% TEN TEN: Field goal
3 Q3 5:38 The 49ers converted 3rd & 73rd & 4th downs · 34% expected +8% SF SF: Turnover on downs
4 Q3 0:04 The Titans converted 3rd & 233rd & 4th downs · 15% expected +16% TEN TEN: Touchdown
5 Q4 13:48 The Titans converted 3rd & 103rd & 4th downs · 26% expected +9% TEN TEN: Touchdown
6 Q4 4:35 The 49ers fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +12% SF SF: Touchdown
7 Q4 0:54 The Titans were stopped on 3rd & 43rd & 4th downs · 44% expected +8% SF TEN: Field goal
8 Q4 0:09 R. Bullock made 44-yard field goalKicks · 81% expected for him +18% TEN –

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.

  • Taylor Lewan (TEN T), out · 1.0 pts
  • Derrick Henry (TEN RB), out (IR) · 0.5 pts
  • Rodger Saffold (TEN G), out (IR) · 0.5 pts
  • Elijah Molden (TEN CB), out (IR) · 0.5 pts
  • David Long (TEN LB), out · 0.4 pts
  • Monty Rice (TEN LB), out (IR) · 0.1 pts
  • Emmanuel Moseley (SF CB), out (IR) · 0.6 pts
  • Mike McGlinchey (SF T), out (IR) · 0.6 pts
  • Mohamed Sanu (SF WR), out (IR) · 0.4 pts
  • Talanoa Hufanga (SF SS), out · 0.4 pts
  • Tavon Wilson (SF SS), out (IR) · 0.2 pts
  • Elijah Mitchell (SF RB), out · 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

49ers 16% · Titans 84%

Final margin
Titans by 3
Luck in points
4.6 for the 49ers
Luck-adjusted margin
Titans by 7.6
Replay with same day's form
49ers 67% · Titans 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 16 2021 games · 49ers · Titans

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