luckadjusted

Week 8 2020 · November 1, 2020

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

Colts at Lions, Week 8 2020: who deserved to win?

The Colts beat the Lions 41–21, and it was no fluke: replayed with the way both teams actually played, the Colts win 8 of 10.

Before kickoff the Colts were 60% favorites. The biggest swing (Q3, 2:34 left): the Lions were stopped on 3rd & 9, worth 27 points of win probability to the Colts.

Final

Indianapolis Colts 41
Detroit Lions 21

November 1, 2020 · Ford Field · Closing line: Colts −3.5

Luck index +19 Colts about even · −19 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. Colts win 8, Lions win 2.

  1. 1 IND 50 DET 21
  2. 2 IND 23 DET 0
  3. 3 IND 39 DET 21
  4. 4 IND 45 DET 30
  5. 5 IND 35 DET 24
  6. 6 IND 31 DET 24
  7. 7 IND 27 DET 23
  8. 8 IND 38 DET 36
  9. 9 IND 24 DET 27
  10. 10 IND 22 DET 34

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

Colts win 81% of them, Lions 19%, counting the 2% still level after regulation as half each. The line is what actually happened: Colts by 20.

Show as a table
Final margin in the replaysShare of replays
Colts by 17+33.9%
Colts by 9–1620.2%
Colts by 1–824.7%
Level after regulation2.2%
Lions by 1–811.9%
Lions by 9–165.5%
Lions by 17+1.7%

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 +8.0 points to the Colts: the final margin was Colts by 20, without the luck Colts by 12. 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.

  • M. Prater, 48 yds missed · 76% expected
  • Extra point missed · 95% expected
  • Extra point missed · 95% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Colts 3 for 19 yards, Lions 4 for 76 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 7:04 Unnecessary Roughness on the Lions (Danny Shelton), 15 yards +6% IND +1.7 pts
Q2 3:54 Fair Catch Interference on the Lions, 15 yards +4% IND +1.4 pts
Q3 9:01 Tripping on the Colts, 10 yards +3% DET +0.9 pts
Q3 6:50 False Start on the Lions (Jamal Agnew), 5 yards · pre-snap +2% IND +0.6 pts
Q4 15:00 Defensive Pass Interference on the Lions, 41 yards +10% IND +4.9 pts
Q4 12:29 Illegal Contact on the Colts (Rock Ya-Sin), 4 yards 0% IND +0.5 pts
Q4 8:54 False Start on the Colts (Michael Pittman Jr.), 5 yards · pre-snap 0% DET +0.6 pts

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

When it happened

Lions’ chance of winning

As low as 0% and as high as 79%. 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 Lions were ahead in it, below while the Colts were.
#WhenWhat happenedWin probability forNext drive
1 Q1 10:54 The Lions fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +6% DET DET: Touchdown
2 Q1 6:29 Blocked punt by the LionsSpecial teams +8% DET DET: Touchdown
3 Q2 7:04 Unnecessary Roughness on the Lions (Danny Shelton), 15 yardsJudgment calls · 4 flags in 932 snaps before, position avg 1 per 262 +6% IND IND: Touchdown
4 Q3 8:11 The Lions converted 3rd & 123rd & 4th downs · 23% expected +8% DET DET: Punt
5 Q3 5:44 The Lions fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +10% DET DET: Turnover
6 Q3 2:34 The Lions were stopped on 3rd & 93rd & 4th downs · 28% expectedThe Lions fumbled and the Colts recoveredFumble bounces · loose balls are close to 50/50 +27% IND DET: Opp touchdown
7 Q4 15:00 Defensive Pass Interference on the Lions, 41 yardsJudgment calls +10% IND IND: Touchdown
8 Q4 13:34 The Colts’ two-point try was good3rd & 4th downs · 47% expectedReturn touchdown by the ColtsSpecial teams +7% IND IND: 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.

  • Desmond Trufant (DET CB), out · 0.6 pts
  • John Atkins (DET DT), out (IR) · 0.3 pts
  • Darryl Roberts (DET CB), out · 0.2 pts
  • Austin Bryant (DET DE), out (IR) · 0.2 pts
  • Malik Hooker (IND FS), out (IR) · 0.4 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

Colts 99% · Lions 1%

Final margin
Colts by 20
Luck in points
8.0 for the Colts
Luck-adjusted margin
Colts by 12.0
Replay with same day's form
Colts 81% · Lions 19% 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 8 2020 games · Colts · Lions

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