luckadjusted

Week 15 2020 · December 20, 2020

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

Lions at Titans, Week 15 2020: who deserved to win?

The Titans beat the Lions 46–25, and it was no fluke: replayed with the way both teams actually played, the Titans win 8 of 10.

Before kickoff the Titans were 76% favorites. The biggest swing (Q3, 9:29 left): the Lions were stopped on 3rd & 1, worth 18 points of win probability to the Titans.

Final

Detroit Lions 25
Tennessee Titans 46

December 20, 2020 · Nissan Stadium · Closing line: Titans −9.5

Luck index +16 Titans about even · −16 Lions

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. Lions win 2, Titans win 8.

  1. 1 DET 38 TEN 28
  2. 2 DET 34 TEN 31
  3. 3 DET 20 TEN 22
  4. 4 DET 24 TEN 28
  5. 5 DET 28 TEN 35
  6. 6 DET 28 TEN 38
  7. 7 DET 23 TEN 36
  8. 8 DET 27 TEN 44
  9. 9 DET 0 TEN 23
  10. 10 DET 20 TEN 48

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

Lions win 16% of them, Titans 84%, counting the 2% still level after regulation as half each. The line is what actually happened: Titans by 21.

Show as a table
Final margin in the replaysShare of replays
Lions by 17+1.4%
Lions by 9–163.4%
Lions by 1–89.6%
Level after regulation1.5%
Titans by 1–820.1%
Titans by 9–1626.0%
Titans by 17+38.0%

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 +6.7 points to the Titans: the final margin was Titans by 21, without the luck Titans by 14.3. 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.

  • S. Gostkowski, 38 yds made · 89% expected
  • M. Prater, 53 yds made · 64% expected
  • Extra point missed · 93% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Lions 3 for 33 yards, Titans 3 for 22 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
Q2 11:50 Defensive Pass Interference on the Lions, 23 yards +3% TEN +1.3 pts
Q2 0:22 False Start on the Titans (Corey Davis), 5 yards · pre-snap +1% DET +0.5 pts
Q3 13:33 False Start on the Lions, 5 yards · pre-snap +3% TEN +0.8 pts
Q3 13:33 Delay of Game on the Lions, 5 yards · pre-snap +1% TEN +0.7 pts
Q3 4:33 Defensive Pass Interference on the Titans (Desmond King), 12 yards +1% DET +0.7 pts
Q4 10:53 False Start on the Titans (MyCole Pruitt), 5 yards · pre-snap 0% DET +0.9 pts

Lions penalties, every game · Titans penalties, every game · All teams, 2020

When it happened

Titans’ chance of winning

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 Lions were.
#WhenWhat happenedWin probability forNext drive
1 Q1 5:26 The Lions converted 3rd & 73rd & 4th downs · 38% expected +6% DET DET: Touchdown
2 Q1 1:38 The Lions converted 3rd & 23rd & 4th downs · 57% expected +8% DET DET: Touchdown
3 Q2 12:56 The Lions were stopped on 3rd & 63rd & 4th downs · 42% expected +4% TEN DET: Punt
4 Q2 4:19 The Lions were stopped on 3rd & 13rd & 4th downs · 71% expectedThe Lions fumbled and the Titans recoveredFumble bounces · loose balls are close to 50/50 +13% TEN DET: Touchdown
5 Q2 0:29 The Titans converted 3rd & 103rd & 4th downs · 30% expected +8% TEN TEN: Field goal
6 Q3 9:29 The Lions were stopped on 3rd & 13rd & 4th downs · 78% expectedThe Lions fumbled and the Titans recoveredFumble bounces · loose balls are close to 50/50 +18% TEN DET: Field goal
7 Q3 4:14 M. Prater made 53-yard field goalKicks · 64% expected for him, 16 of 26 from 45+ before +5% DET DET: Turnover on downs
8 Q3 2:46 The Titans converted 3rd & 113rd & 4th downs · 29% expected +10% TEN TEN: 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.

  • Breon Borders (TEN CB), out (IR) · 0.6 pts
  • Jadeveon Clowney (TEN OLB), out (IR) · 0.6 pts
  • Kenny Vaccaro (TEN S), out · 0.5 pts
  • Ty Sambrailo (TEN T), out (IR) · 0.4 pts
  • Jayon Brown (TEN LB), out (IR) · 0.4 pts
  • Geoff Swaim (TEN TE), out · 0.2 pts
  • Frank Ragnow (DET OL), out · 0.8 pts
  • Desmond Trufant (DET CB), out (IR) · 0.8 pts
  • Kenny Golladay (DET WR), out · 0.5 pts
  • Trey Flowers (DET DE), out (IR) · 0.4 pts
  • Tyrell Crosby (DET OL), out · 0.4 pts
  • Danny Shelton (DET DT), out (IR) · 0.3 pts
  • Darryl Roberts (DET CB), out · 0.2 pts
  • Da'Shawn Hand (DET DL), out (IR) · 0.2 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

Lions 0% · Titans 100%

Final margin
Titans by 21
Luck in points
6.6 for the Titans
Luck-adjusted margin
Titans by 14.4
Replay with same day's form
Lions 16% · Titans 84% 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 2020 games · Lions · Titans

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