luckadjusted
NHL Week 1 · 2026-27

2025-26 regular season · December 16, 2025

No betting line for this game, so there is no before-puck-drop or fresh-game number.

Mammoth at Bruins, Dec 16, 2025: who deserved to win?

The Bruins beat the Mammoth 4–1, but the replays call it close to a coin flip: with the way both teams played, the Bruins win 5 of 10. Luck ran their way: goaltending alone was worth 18 points of win probability to the Bruins.

The biggest swing (P1, 11:26 left): Barrett Hayton scored on a tip from 16 feet, worth 16 points of win probability to the Mammoth.

Final

Utah Mammoth 1
Boston Bruins 4

December 16, 2025 · TD Garden

Luck index +51 Bruins lucky · −51 Mammoth

Each team’s own shots from this game, resampled into new games 4,000 times, each a goal at its chance, with the power plays the penalties gave and the pulled goalie at the end: with the way both teams actually played, how often does this performance win? How the replay works

Ten replays. Mammoth win 5, Bruins win 5.

  1. 1 UTA 6 BOS 2
  2. 2 UTA 4 BOS 1
  3. 3 UTA 4 BOS 2
  4. 4 UTA 4 BOS 3
  5. 5 UTA 2 BOS 1
  6. 6 UTA 3 BOS 4
  7. 7 UTA 1 BOS 2
  8. 8 UTA 1 BOS 3
  9. 9 UTA 3 BOS 5
  10. 10 UTA 1 BOS 4

Three other ways to ask

Each answers a different question, so none of them replaces the replay above.

No closing line for this game.

Needs the closing line, which this game has not got.

Every shot redrawn at its chance, overtime and the shootout replayed as near coin flips; the shots themselves and every call fixed. The narrowest view of luck.

How 3,999.9 replays ended

Mammoth win 51% of them, Bruins 49%. The line is what actually happened: Bruins by 3.

Show as a table
Final margin in the replaysShare of replays
Mammoth by 3+17.6%
Mammoth by 210.7%
Mammoth by 122.9%
Bruins by 122.8%
Bruins by 210.1%
Bruins by 3+15.8%

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 post hit in a blowout counts for nothing; the same post with a minute left in 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 +2.2 goals to the Bruins: the final margin was Bruins by 3, without the luck Bruins by 0.8. Luck shares are the fitted ones (how much of each kind is luck).
ShootingUnblocked attemptsGoalsExpected goalsAbove expected
Mammoth3512.32−1.32
Bruins3542.35+1.65

Regulation with both goalies in. Expected goals: our model of each shot’s chance from where and how it was taken (distance, angle, shot type, rebound, rush, strength), adjusted for the shooter’s and the goalie’s records. A team above expected finished better or met a weaker night in goal; 75% of the gap counts as luck (why that share).

Calls

Every penalty that put a team on the power play, and every goal taken off the board on review, with what it did to the helped team’s chance of winning at that moment. Calls don’t count toward luck by default: who draws penalties repeats from game to game like a skill (how calls are valued). Switch them on below.

WhenCallWin probability for
P1 13:12 Tripping on the Bruins (Pavel Zacha): 2 minutes on the power play +4% UTA
P1 5:11 Slashing on the Mammoth (JJ Peterka): 2 minutes on the power play +4% BOS
P2 18:54 Tripping on the Mammoth (Nate Schmidt): 2 minutes on the power play +4% BOS
P2 12:50 Holding on the Bruins (Michael Eyssimont): 2 minutes on the power play +4% UTA
P2 5:22 Interference on the Mammoth (Barrett Hayton): 2 minutes on the power play +4% BOS
P3 18:11 Slashing on the Bruins (Mason Lohrei): 2 minutes on the power play +5% UTA
P3 0:26 Slashing on the Mammoth (Nick Schmaltz): 2 minutes on the power play 0% BOS

When it happened

Bruins’ chance of winning

As low as 35% and as high as 100%. Numbers mark the biggest luck moments, listed below.

Our in-game win probability: the score and the time left, starting from the betting line (or the home edge alone when there is none), with goals at the league’s rates for the score. Overtime is drawn at a fixed width. Shaded above the middle while the Bruins were ahead in it, below while the Mammoth were.
#WhenWhat happenedWin probability forNext drive
1 P1 11:26 Barrett Hayton scored on a tip from 16 feetShooting · 5% chance +16% UTA –
2 P1 3:59 Morgan Geekie scored on a wrist shot from 20 feetShooting · 14% chance +16% BOS –
3 P1 1:04 Jack McBain’s wrist shot from 5 feet was savedShooting · 22% chance +4% BOS –
4 P2 19:37 Morgan Geekie scored on a wrist shot from 7 feetShooting · 24% chance +14% BOS –
5 P2 12:50 Holding on the Bruins (Michael Eyssimont): 2 minutes on the power playPenalty calls +4% UTA –
6 P2 5:22 Interference on the Mammoth (Barrett Hayton): 2 minutes on the power playPenalty calls +4% BOS –
7 P3 18:11 Slashing on the Bruins (Mason Lohrei): 2 minutes on the power playPenalty calls +5% UTA –
8 P3 9:44 Casey Mittelstadt scored on a wrist shot from 13 feetShooting · 9% chance +12% BOS –

Adjust the assumptions

Think finishing is more skill than we do, or that the calls were luck? Change it and the coin-flip replay reruns in your browser.

Only coin-flips re-rolled

Mammoth 31% · Bruins 69%

Final margin
Bruins by 3
Luck in goals
2.2 for the Bruins
Luck-adjusted margin
Bruins by 0.8
Replay with same day's form
Mammoth 51% · Bruins 49% unchanged: why
How much of each is luck?

0% treats it as skill, 100% as pure luck. The tick is our fit.

What counts
Flip a play

Force the other outcome, in this game and in every replay: a goal becomes a save, a post goes in, a penalty goes the other way.

About these numbers

Play-by-play from the NHL via fastRhockey; expected goals, in-game win probability and the replays are our own models, fitted on every game since 2018-19 (methodology and validation). Blocked shots aren’t replayed (their location is the block’s, not the shot’s). No betting line for this game, so there is no before-puck-drop or fresh-game number.

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