luckadjusted

Week 16 2020 · December 27, 2020

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

Colts at Steelers, Week 16 2020: who deserved to win?

The Steelers beat the Colts 28–24, but it was a coin flip: replayed with the way both teams played, the Steelers win 5 of 10. Luck ran their way: fumble bounces alone were worth 11 points of win probability to the Steelers.

Before kickoff it was a pick’em. The biggest swing (Q4, 1:55 left): Defensive Pass Interference on the Steelers (Steven Nelson), 9 yards, wiping out the play, worth 26 points of win probability to the Colts.

Final

Indianapolis Colts 24
Pittsburgh Steelers 28

December 27, 2020 · Heinz Field · Closing line: Colts −1

Luck index +47 Steelers lucky · −47 Colts

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 5, Steelers win 5.

  1. 1 IND 54 PIT 30
  2. 2 IND 32 PIT 17
  3. 3 IND 30 PIT 21
  4. 4 IND 27 PIT 22
  5. 5 IND 16 PIT 14
  6. 6 IND 20 PIT 23
  7. 7 IND 17 PIT 24
  8. 8 IND 20 PIT 32
  9. 9 IND 37 PIT 54
  10. 10 IND 19 PIT 46

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 47% of them, Steelers 53%, counting the 5% still level after regulation as half each. The line is what actually happened: Steelers by 4.

Show as a table
Final margin in the replaysShare of replays
Colts by 17+11.3%
Colts by 9–1613.1%
Colts by 1–821.4%
Level after regulation4.9%
Steelers by 1–820.9%
Steelers by 9–1614.9%
Steelers by 17+13.5%

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 +5.0 points to the Steelers: the final margin was Steelers by 4, without the luck Colts by 1. Luck shares are the fitted ones (how much of each kind is luck).

Penalties: Colts 9 for 83 yards, Steelers 6 for 49 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
Q1 5:42 Offensive Holding on the Colts (Zaire Franklin), 4 yards +1% PIT +0.4 pts
Q2 13:51 Defensive Offside on the Colts (Kemoko Turay), 1 yard · pre-snap 0% PIT +0.7 pts
Q2 13:47 Offensive Holding on the Colts (E.J. Speed), 10 yards +2% PIT +0.8 pts
Q2 5:02 Illegal Block Above the Waist on the Steelers (Justin Layne), 10 yards +2% IND +0.9 pts
Q2 4:02 Offensive Holding on the Steelers, 10 yards +1% IND +0.9 pts
Q2 1:23 Illegal Block Above the Waist on the Colts, 10 yards, wiping out the play +13% PIT +6.8 pts
Q2 1:10 Delay of Game on the Colts, 5 yards · pre-snap +1% PIT +0.2 pts
Q3 9:36 Encroachment on the Steelers (Tyson Alualu), 5 yards · pre-snap +1% IND +0.2 pts
Q3 9:23 Offensive Holding on the Steelers (Avery Williamson), 10 yards +1% IND +1.0 pts
Q3 5:54 Defensive Pass Interference on the Colts (Xavier Rhodes), 3 yards +1% PIT +0.4 pts
Q3 1:39 Defensive Pass Interference on the Colts, 24 yards +5% PIT +2.0 pts
Q4 15:00 Defensive Pass Interference on the Colts (T.J. Carrie), 21 yards +7% PIT +2.1 pts
Q4 9:04 False Start on the Steelers (Eric Ebron), 5 yards · pre-snap +6% IND +0.6 pts
Q4 7:48 Illegal Contact on the Colts (Xavier Rhodes), 5 yards +7% PIT +0.6 pts
Q4 1:55 Defensive Pass Interference on the Steelers (Steven Nelson), 9 yards, wiping out the play +26% IND +6.9 pts

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

When it happened

Steelers’ chance of winning

As low as 5% 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 Steelers were ahead in it, below while the Colts were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:06 The Colts converted 3rd & 83rd & 4th downs · 32% expected +8% IND IND: Touchdown
2 Q2 14:46 The Colts fumbled and the Steelers recoveredFumble bounces · loose balls are close to 50/50 +10% PIT IND: Touchdown
3 Q2 1:23 Illegal Block Above the Waist on the Colts, 10 yards, wiping out the playJudgment calls +13% PIT PIT: End of half
4 Q4 12:57 The Colts were stopped on 3rd & 53rd & 4th downs · 41% expected +8% PIT IND: Punt
5 Q4 8:19 The Steelers converted 3rd & 53rd & 4th downs · 41% expected +8% PIT PIT: Touchdown
6 Q4 1:55 Defensive Pass Interference on the Steelers (Steven Nelson), 9 yards, wiping out the playJudgment calls · 4 flags in 1912 snaps before, position avg 1 per 207 +26% IND IND: Turnover on downs
7 Q4 1:39 The Colts converted 3rd & 63rd & 4th downs · 37% expected +13% IND IND: Turnover on downs
8 Q4 1:19 The Colts were stopped on 4th & 83rd & 4th downs · 31% expected +20% PIT –

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.

  • Chris Boswell (PIT K), out · 0.3 pts
  • Matt Feiler (PIT G), out (IR) · 0.3 pts
  • Bud Dupree (PIT LB), out (IR) · 0.3 pts
  • Robert Spillane (PIT LB), out (IR) · 0.3 pts
  • Matt Feiler (PIT OT), out (IR) · 0.2 pts
  • Anthony Castonzo (IND T), out · 1.1 pts
  • Braden Smith (IND T/G), 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 55% · Steelers 45%

Final margin
Steelers by 4
Luck in points
5.0 for the Steelers
Luck-adjusted margin
Colts by 1.0
Replay with same day's form
Colts 47% · Steelers 53% 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 2020 games · Colts · Steelers

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