luckadjusted

Week 2 2020 · September 20, 2020

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

Broncos at Steelers, Week 2 2020: who deserved to win?

The Steelers beat the Broncos 26–21 and were the better team on the day: replayed with the same form, they win 6 of 10. The Broncos had the bounces: judgment calls alone were worth 30 points of win probability to the Broncos.

Before kickoff the Steelers were 67% favorites. The biggest swing (Q4, 1:55 left): the Broncos were stopped on 4th & 2, worth 25 points of win probability to the Steelers.

Final

Denver Broncos 21
Pittsburgh Steelers 26

September 20, 2020 · Heinz Field · Closing line: Steelers −6

Luck index +36 Steelers lucky · −36 Broncos

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. Broncos win 4, Steelers win 6.

  1. 1 DEN 33 PIT 13
  2. 2 DEN 29 PIT 17
  3. 3 DEN 30 PIT 23
  4. 4 DEN 16 PIT 14
  5. 5 DEN 31 PIT 33
  6. 6 DEN 17 PIT 23
  7. 7 DEN 10 PIT 20
  8. 8 DEN 23 PIT 37
  9. 9 DEN 16 PIT 36
  10. 10 DEN 3 PIT 30

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

Broncos win 36% of them, Steelers 64%, counting the 3% still level after regulation as half each. The line is what actually happened: Steelers by 5.

Show as a table
Final margin in the replaysShare of replays
Broncos by 17+6.6%
Broncos by 9–1610.8%
Broncos by 1–817.9%
Level after regulation2.6%
Steelers by 1–821.3%
Steelers by 9–1619.2%
Steelers by 17+21.6%

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 +7.5 points to the Broncos: the final margin was Steelers by 5, without the luck Steelers by 12.4. 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.

  • B. McManus, 49 yds made · 74% expected
  • B. McManus, 58 yds missed · 60% expected
  • C. Boswell, 21 yds made · 100% expected
  • B. McManus, 28 yds made · 97% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Broncos 4 for 30 yards, Steelers 10 for 89 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 13:47 Defensive Pass Interference on the Steelers (Joe Haden), 4 yards +5% DEN +1.3 pts
Q2 14:27 False Start on the Broncos (Nick Vannett), 5 yards · pre-snap +1% PIT +0.7 pts
Q2 10:37 Offensive Holding on the Steelers (Vance McDonald), 10 yards +1% DEN +0.8 pts
Q2 6:56 Illegal Block Above the Waist on the Steelers (Cameron Sutton), 10 yards +3% DEN +1.0 pts
Q2 4:11 Offensive Holding on the Steelers (Eric Ebron), 10 yards +1% PIT +1.2 pts
Q2 2:22 Delay of Game on the Steelers, 5 yards · pre-snap 0% DEN +0.2 pts
Q3 12:08 Illegal Block Above the Waist on the Broncos, 10 yards +1% PIT +0.9 pts
Q3 9:07 Horse Collar Tackle on the Steelers (Minkah Fitzpatrick), 4 yards +1% DEN +0.9 pts
Q3 7:21 Neutral Zone Infraction on the Broncos (Bradley Chubb), 5 yards · pre-snap +2% PIT +0.8 pts
Q3 2:33 Defensive Pass Interference on the Steelers (Minkah Fitzpatrick), 5 yards +2% DEN +1.3 pts
Q3 1:17 Roughing the Passer on the Steelers, 15 yards +7% DEN +1.4 pts
Q4 9:41 Offensive Holding on the Broncos, 10 yards +1% PIT +0.9 pts
Q4 9:02 Defensive Pass Interference on the Steelers (Devin Bush Jr.), 9 yards 0% PIT +0.3 pts
Q4 3:19 Defensive Pass Interference on the Steelers (Terrell Edmunds), 17 yards +13% DEN +2.3 pts

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

When it happened

Steelers’ chance of winning

As low as 47% 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 Broncos were.
#WhenWhat happenedWin probability forNext drive
1 Q1 7:53 The Broncos were stopped on 3rd & 73rd & 4th downs · 31% expectedThe Broncos fumbled and the Steelers recoveredFumble bounces · loose balls are close to 50/50 +20% PIT DEN: Punt
2 Q1 5:04 The Steelers converted 3rd & 103rd & 4th downs · 27% expected +6% PIT PIT: Touchdown
3 Q2 7:39 The Broncos were stopped on 3rd & 43rd & 4th downs · 43% expected +7% PIT DEN: Punt
4 Q3 1:17 Roughing the Passer on the Steelers, 15 yardsJudgment calls +7% DEN DEN: Touchdown
5 Q4 12:35 The Steelers converted 4th & 23rd & 4th downs · 59% expected +6% PIT PIT: Touchdown
6 Q4 3:19 Defensive Pass Interference on the Steelers (Terrell Edmunds), 17 yardsJudgment calls · 2 flags in 1173 snaps before, position avg 1 per 237 +13% DEN DEN: Turnover on downs
7 Q4 2:00 The Broncos were stopped on 3rd & 23rd & 4th downs · 58% expected +8% PIT DEN: Turnover on downs
8 Q4 1:55 The Broncos were stopped on 4th & 23rd & 4th downs · 57% expected +25% 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.

  • David DeCastro (PIT G), out · 0.7 pts
  • Von Miller (DEN LB), out (IR) · 0.5 pts
  • Phillip Lindsay (DEN RB), out · 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

Broncos 2% · Steelers 98%

Final margin
Steelers by 5
Luck in points
7.5 for the Broncos
Luck-adjusted margin
Steelers by 12.5
Replay with same day's form
Broncos 36% · Steelers 64% 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 2 2020 games · Broncos · Steelers

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