luckadjusted

Week 1 2026 · September 14, 2026

Broncos at Chiefs, Week 1 2026: who deserved to win?

The Chiefs beat the Broncos 31–10, and it was no fluke: replayed with the way both teams actually played, the Chiefs win 9 of 10.

Before kickoff the Chiefs were 57% favorites. The biggest swing (Q3, 12:53 left): the Chiefs converted 4th & 1, worth 12 points of win probability to the Chiefs.

Final

Denver Broncos 10
Kansas City Chiefs 31

September 14, 2026 · GEHA Field at Arrowhead Stadium · Closing line: Chiefs −2.5

Luck index +14 Chiefs about even · −14 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 1, Chiefs win 9.

  1. 1 DEN 16 KC 10
  2. 2 DEN 14 KC 16
  3. 3 DEN 20 KC 24
  4. 4 DEN 10 KC 17
  5. 5 DEN 3 KC 13
  6. 6 DEN 7 KC 19
  7. 7 DEN 17 KC 31
  8. 8 DEN 21 KC 38
  9. 9 DEN 12 KC 34
  10. 10 DEN 6 KC 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

Broncos win 14% of them, Chiefs 86%, counting the 2% still level after regulation as half each. The line is what actually happened: Chiefs by 21.

Show as a table
Final margin in the replaysShare of replays
Broncos by 17+0.9%
Broncos by 9–162.8%
Broncos by 1–88.8%
Level after regulation1.9%
Chiefs by 1–820.1%
Chiefs by 9–1625.1%
Chiefs by 17+40.4%

Where the luck was

Take the luck out

The final margin was Chiefs by 21. Remove the luck, one kind at a time, and it becomes Chiefs by 16.0.

Each row takes one kind of luck out of the margin. Color shows which team it helped. Luck shares are the fitted ones (how much of each component is luck).

The kicks

How likely each kicker was to make that kick (his own record, the distance and the weather), and what happened.

  • W. Lutz, 31 yds made · 94% expected
  • H. Butker, 28 yds made · 98% expected
Bar: expected chance of a make. Filled dot: made. Open dot: missed or blocked.

When it happened

Chiefs’ chance of winning

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 Chiefs were ahead in it, below while the Broncos were.
#WhenWhat happenedWin probability forNext drive
1 Q1 13:39 The Broncos were stopped on 3rd & 113rd & 4th downs · 25% expectedThe Broncos threw an interception-worthy pass, and it was pickedInterceptions · 48% expected to stay out of the defense's hands +8% KC DEN: Touchdown
2 Q1 11:35 The Chiefs converted 4th & 23rd & 4th downs · 58% expected +6% KC KC: Touchdown
3 Q1 8:27 Offensive Holding on the Chiefs, 10 yards, wiping out the playJudgment calls +5% DEN DEN: Touchdown
4 Q2 11:21 The Chiefs fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +6% KC KC: Punt
5 Q2 8:41 The Chiefs converted 3rd & 83rd & 4th downs · 30% expected +6% KC KC: Punt
6 Q2 4:37 K. Walker dropped a catchable passDrops · 10 drops on 155 catchable balls before this +6% DEN KC: Touchdown
7 Q2 4:33 The Chiefs converted 3rd & 103rd & 4th downs · 26% expectedThe Chiefs fumbled and recovered it themselvesFumble bounces · loose balls are close to 50/50 +11% KC KC: Touchdown
8 Q3 12:53 The Chiefs converted 4th & 13rd & 4th downs · 72% expected +12% KC KC: 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.

  • Chamarri Conner (KC DB), out · 0.8 pts
  • Josh Simmons (KC T), out · 0.7 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 1% · Chiefs 99%

Final margin
Chiefs by 21
Luck in points
5.1 for the Chiefs
Luck-adjusted margin
Chiefs by 15.9
Replay with same day's form
Broncos 14% · Chiefs 86% 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; injuries from snap counts and injury reports.

Methodology and validation · All Week 1 2026 games · Broncos · Chiefs

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