luckadjusted

Week 6 2021 · October 17, 2021

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

Seahawks at Steelers, Week 6 2021: who deserved to win?

The Steelers beat the Seahawks 23–20 and were the better team on the day: replayed with the same form, they win 7 of 10. The Seahawks had the bounces: fumble bounces alone were worth 54 points of win probability to the Seahawks.

Before kickoff the Steelers were 66% favorites. The biggest swing (Q4, 0:18 left): the Seahawks fumbled and recovered it themselves, worth 41 points of win probability to the Seahawks.

Final (OT)

Seattle Seahawks 20
Pittsburgh Steelers 23

October 17, 2021 · Heinz Field · Closing line: Steelers −5.5

Luck index +27 Steelers lucky · −27 Seahawks

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. Seahawks win 3, Steelers win 7.

  1. 1 SEA 24 PIT 6
  2. 2 SEA 38 PIT 28
  3. 3 SEA 23 PIT 20
  4. 4 SEA 31 PIT 34
  5. 5 SEA 37 PIT 43
  6. 6 SEA 19 PIT 28
  7. 7 SEA 28 PIT 41
  8. 8 SEA 17 PIT 33
  9. 9 SEA 3 PIT 24
  10. 10 SEA 20 PIT 50

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

Seahawks win 27% of them, Steelers 73%, counting the 2% still level after regulation as half each. The line is what actually happened: Steelers by 3.

Show as a table
Final margin in the replaysShare of replays
Seahawks by 17+4.4%
Seahawks by 9–167.8%
Seahawks by 1–813.1%
Level after regulation2.5%
Steelers by 1–823.1%
Steelers by 9–1618.6%
Steelers by 17+30.6%

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 +2.5 points to the Steelers: the final margin was Steelers by 3, without the luck Steelers by 0.5. 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.

  • C. Boswell, 27 yds made · 99% expected
  • J. Myers, 40 yds made · 87% expected
  • C. Boswell, 52 yds made · 72% expected
  • J. Myers, 43 yds made · 83% expected
  • C. Boswell, 37 yds made · 92% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Seahawks 6 for 45 yards, Steelers 5 for 38 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 13:31 False Start on the Steelers, 5 yards · pre-snap +3% SEA +0.7 pts
Q1 8:04 False Start on the Seahawks, 5 yards · pre-snap +1% PIT +0.8 pts
Q1 5:08 Delay of Game on the Seahawks, 5 yards · pre-snap +5% PIT +0.6 pts
Q1 4:14 Offensive Pass Interference on the Steelers (Diontae Johnson), 10 yards, wiping out the play +7% SEA +1.8 pts
Q2 4:35 Face Mask on the Seahawks, 15 yards +4% PIT +1.8 pts
Q2 2:57 Defensive Offside on the Seahawks (Alton Robinson), 5 yards · pre-snap +1% PIT +0.9 pts
Q3 10:36 Unnecessary Roughness on the Steelers (T.J. Watt), 3 yards +1% SEA +0.4 pts
Q3 7:36 Illegal Block Above the Waist on the Steelers (Chase Claypool), 10 yards +1% SEA +0.8 pts
Q3 3:02 Illegal Formation on the Seahawks (Darrell Taylor), 5 yards · pre-snap 0% PIT +0.4 pts
Q4 11:32 Offensive Holding on the Seahawks, 10 yards, wiping out the play +17% PIT +2.5 pts
Q4 2:00 Offensive Pass Interference on the Steelers (Chase Claypool), 10 yards +8% SEA +1.0 pts

Seahawks penalties, every game · Steelers penalties, every game · All teams, 2021

When it happened

Steelers’ chance of winning

As low as 25% 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 Seahawks were.
#WhenWhat happenedWin probability forNext drive
1 Q3 0:06 The Seahawks converted 3rd & 73rd & 4th downs · 33% expected +14% SEA SEA: Field goal
2 Q4 13:47 The Seahawks were stopped on 3rd & 23rd & 4th downs · 51% expected +15% PIT SEA: Field goal
3 Q4 11:37 The Steelers fumbled and the Seahawks recoveredFumble bounces · loose balls are close to 50/50 +9% SEA PIT: Punt
4 Q4 11:32 Offensive Holding on the Seahawks, 10 yards, wiping out the playJudgment calls +17% PIT PIT: Punt
5 Q4 1:48 The Steelers were stopped on 3rd & 153rd & 4th downs · 21% expected +10% PIT PIT: Field goal
6 Q4 0:22 The Seahawks fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +32% SEA SEA: Field goal
7 Q4 0:18 The Seahawks fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +41% SEA SEA: Field goal
8 QOT 7:17 The Seahawks were stopped on 3rd & 43rd & 4th downs · 44% expected +28% PIT SEA: Punt

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.

  • JuJu Smith-Schuster (PIT WR), out (IR) · 0.9 pts
  • Stephon Tuitt (PIT DE), out (IR) · 0.8 pts
  • Tyson Alualu (PIT DE), out (IR) · 0.4 pts
  • Russell Wilson (SEA QB), out (IR), replaced by g.smith · 6.2 pts
  • Cedric Ogbuehi (SEA T), out · 0.4 pts
  • Chris Carson (SEA RB), out (IR) · 0.3 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

Seahawks 23% · Steelers 77%

Final margin
Steelers by 3
Luck in points
2.5 for the Steelers
Luck-adjusted margin
Steelers by 0.5
Replay with same day's form
Seahawks 27% · Steelers 73% 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 6 2021 games · Seahawks · Steelers

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