luckadjusted

Week 1 2021 · September 12, 2021

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

Broncos at Giants, Week 1 2021: who deserved to win?

The Broncos beat the Giants 27–13 and were the better team on the day: replayed with the same form, they win 7 of 10.

Before kickoff the Broncos were 59% favorites. The biggest swing (Q1, 14:14 left): the Giants converted 3rd & 5, worth 11 points of win probability to the Giants.

Final

Denver Broncos 27
New York Giants 13

September 12, 2021 · MetLife Stadium · Closing line: Broncos −3

Luck index +27 Broncos lucky · −27 Giants

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 7, Giants win 3.

  1. 1 DEN 38 NYG 13
  2. 2 DEN 31 NYG 13
  3. 3 DEN 34 NYG 20
  4. 4 DEN 24 NYG 13
  5. 5 DEN 27 NYG 19
  6. 6 DEN 30 NYG 24
  7. 7 DEN 16 NYG 14
  8. 8 DEN 16 NYG 19
  9. 9 DEN 7 NYG 14
  10. 10 DEN 7 NYG 23

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 73% of them, Giants 27%, counting the 5% still level after regulation as half each. The line is what actually happened: Broncos by 14.

Show as a table
Final margin in the replaysShare of replays
Broncos by 17+21.4%
Broncos by 9–1622.6%
Broncos by 1–827.1%
Level after regulation4.9%
Giants by 1–815.0%
Giants by 9–166.8%
Giants by 17+2.1%

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 +1.1 points to the Giants: the final margin was Broncos by 14, without the luck Broncos by 15.1. 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, 23 yds made · 99% expected
  • B. McManus, 36 yds made · 90% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

Penalties: Broncos 5 for 51 yards, Giants 4 for 48 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 12:30 Delay of Game on the Giants, 5 yards · pre-snap +5% DEN 0.0 pts
Q1 5:36 Illegal Block Above the Waist on the Broncos (Courtland Sutton), 10 yards +2% NYG +1.2 pts
Q2 11:19 Defensive Pass Interference on the Broncos (Ronald Darby), 5 yards +5% NYG +2.2 pts
Q2 5:22 Unnecessary Roughness on the Giants (Darnay Holmes), 13 yards +6% DEN +1.3 pts
Q3 0:02 Unnecessary Roughness on the Giants (Danny Shelton), 15 yards +2% DEN +1.4 pts
Q4 12:00 Unnecessary Roughness on the Broncos (Dre'Mont Jones), 15 yards 0% NYG +1.9 pts
Q4 7:18 Defensive Pass Interference on the Broncos (Kyle Fuller), 6 yards +2% NYG +1.1 pts
Q4 4:54 Roughing the Passer on the Giants (Azeez Ojulari), 15 yards +1% DEN +1.8 pts
Q4 4:37 Unnecessary Roughness on the Broncos, 15 yards 0% NYG +1.4 pts

Broncos penalties, every game · Giants penalties, every game · All teams, 2021

When it happened

Giants’ chance of winning

As low as 0% and as high as 65%. 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 Giants were ahead in it, below while the Broncos were.
#WhenWhat happenedWin probability forNext drive
1 Q1 14:14 The Giants converted 3rd & 53rd & 4th downs · 40% expected +11% NYG NYG: Punt
2 Q1 7:53 The Giants were stopped on 3rd & 23rd & 4th downs · 60% expected +8% DEN NYG: Punt
3 Q1 2:10 The Broncos converted 4th & 73rd & 4th downs · 33% expected +10% DEN DEN: Field goal
4 Q2 9:49 The Giants converted 3rd & 53rd & 4th downs · 40% expected +8% NYG NYG: Touchdown
5 Q2 4:17 The Broncos fumbled and the Giants recoveredFumble bounces · loose balls are close to 50/50 +7% NYG DEN: Touchdown
6 Q2 0:48 The Broncos converted 4th & 23rd & 4th downs · 60% expected +11% DEN DEN: Touchdown
7 Q3 8:50 The Broncos converted 3rd & 73rd & 4th downs · 34% expected +7% DEN DEN: Touchdown
8 Q3 2:03 The Broncos converted 3rd & 83rd & 4th downs · 32% expected +7% DEN DEN: Field goal

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.

  • Evan Engram (NYG TE), out · 0.9 pts
  • Bradley Chubb (DEN OLB), out · 0.6 pts
  • Michael Ojemudia (DEN CB), out (IR) · 0.3 pts
  • Essang Bassey (DEN CB), 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

Broncos 100% · Giants 0%

Final margin
Broncos by 14
Luck in points
1.1 for the Giants
Luck-adjusted margin
Broncos by 15.1
Replay with same day's form
Broncos 73% · Giants 27% 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 1 2021 games · Broncos · Giants

More from Week 1 2021