Motion-blurred skater in a Buffalo Sabres sweater

Breakdown · BOS at BUF

Sabres run the Bruins off the ice on the underlying numbers

FinalSat, Dec 27

The verdict · earned

The Sabres earned it — the game and the expected-goals battle both.

BOS 1 · BUF 4

◆ By the ModelJul 11, 9:53 PMxG: xgboost-0.758Edited for clarityDrafted from NHL play-by-play by Backcheck's model, worded for clarity by an AI editor that may not change a number. Nobody at Backcheck was at the rink. How this works

The Bruins were convincingly beaten, but the scoreboard (4–1) barely captures how much they were outplayed. Buffalo controlled 62% of expected goals at 5v5 (4.19–2.54), and Boston's goaltending collapse—underperforming by 1.54 goals—obscures an even larger quality gap.

The Sabres' advantage wasn't volume but precision. They generated 0.072 expected goals per shot versus Boston's 0.045—a 60% gap in shot quality. That translates to pressure: on 27 rush chances, Buffalo scored four times, a devastating conversion rate. Boston crashed the net for six rebound opportunities and converted zero. The Bruins created chances but couldn't finish the dirty work.

U. Luukkonen (BUF) stole the show with 1.54 goals saved above expected—an elite performance. J. Korpisalo (BOS) played the other side: he saved 1.19 above expected yet still allowed four goals, a sign of how badly Boston's defense abandoned him. The scoreline could've been much worse for Boston if Luukkonen had posted league-average numbers.

Josh Norris's wrist shot from the top of the circles early in the third period (P3, 19:46) ignited Buffalo's dominance, but the real story unfolded in the underlying data: the Sabres were faster, smarter, and more purposeful. M. Samuelsson (1G, 2A) and T. Thompson (2A) orchestrated the offense, while P. Krebs (1G, 1A) chipped in on secondary chances.

Boston had one overarching problem: they needed their goaltender to steal the game, and the margin of error was gone before the puck even dropped.

The breakdown in twelve frames

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Every number is from this page

Final · Dec 27

BOS

BUF

Sabres run the Bruins off the ice on the underlying numbers

Chances 2.5 – 4.2Did they deserve it? →

Did they deserve it?

The Sabres earned this one.

Expected goals · chance value

BOS

2.54

BUF

4.19

38% of the chances62%

The board read BOS 1, BUF 4. The chances read BOS 2.5, BUF 4.2.

Our xG model · NHL play-by-play · all situations

Luck check

BUF

−0.2

goals above expected

BUF4.19 expected · 4 scored

Expected

Scored

BOS2.54 expected · 1 scored

Expected

Scored

The Bruins left 1.5 goals on the table against what their chances were worth.

PDO = sh% + sv% · drifts to 1.000 over a season

Every goal, in order

P1 11:56BOSD. Pastrnak1–0
P2 01:39BUFR. McLeod1–1
P2 03:12BUFP. Krebs1–2
P2 07:54BUFM. Samuelsson1–3
P3 19:46BUFJ. NorrisEN1–4

NHL play-by-play · chance value from our xG model

Where the shots came from

BOS

43 shots

Final

87 shots

BUF

44 shots

BOS BUF GoalBigger dot · more dangerous look

shots · 1 in

shots · 4 in

Every unblocked shot · press play to replay it

Chances by danger

BOSBUF

0 / 2

0.37 xG

High danger

1 / 6

2.01 xG

0 / 15

1.53 xG

Medium

1 / 14

1.58 xG

1 / 40

0.64 xG

Low

2 / 38

0.59 xG

High-danger looks: BOS 0 of 2, BUF 1 of 6.

Danger tiers by our xG model · high ≥ 20% chance

In the net

U. Luukkonen

+1.5

BUF · 22/23

B+

J. Korpisalo

+1.2

BOS · 30/33

The numbers, checked

BACKCHECK

Sabres run the Bruins off the ice on the underlying numbers

A model, not a newsroom. Every number on these frames comes from the NHL's play-by-play and our own models. Nothing was watched, guessed or heard from anyone.

Read the full breakdown

backcheckreport.com

01 / 08 · Final

Every goal, in order

How it happened

NHL play-by-play

1stshots 9–13

11:56BOSD. Pastrnak(M. Geekie)1–0

2ndshots 3–13

01:39BUFR. McLeod(J. Quinn, M. Samuelsson)1–1
03:12BUFP. Krebs(T. Thompson, M. Samuelsson)1–2
07:54BUFM. Samuelsson(J. Quinn, B. Byram)1–3

3rdshots 11–8

19:46BUFJ. Norrisempty net(P. Krebs, T. Thompson)1–4

score reads BOS–BUF

Source · NHL play-by-play (api-web.nhle.com)

Process vs result

The numbers

XGBoost xG · NHL play-by-play

4.19

BUF chances

Goals their shots were worth

−0.2

Finishing

Goals below what those chances were worth

1.051

BUF puck luck

Above 1.000 — the bounces went their way

50.4%

Shot attempts

Over half — they had the puck more

Split by club

Who controlled the game

2.54Expected goals4.19

BUF 62% of the chance quality

23Shots on goal34

2High-danger chances6

57All attempts (Corsi)58

Adjusted for score: BOS 53% · BUF 47%

Faceoffs · BUF won30%off62%neu42%def

Source · NHL play-by-play · XGBoost xG

How the game was won

The danger ladder

shotsgoalsexpected

High dangerslot & crease

BOS0 / 2 · 0.37 xG

BUF1 / 6 · 2.01 xG

Medium dangermid-range

BOS0 / 15 · 1.53 xG

BUF1 / 14 · 1.58 xG

Low dangerperimeter & point

BOS1 / 40 · 0.64 xG

BUF2 / 38 · 0.59 xG

BOS went 0-for-15 from medium danger on 1.53 expected goals — 1.5 left on the table.

Source · Backcheck xG model · NHL play-by-play

The luck layer

Finishing vs expected

expectedactual

BOS

1 G · 2.54 xG · -1.5

BUF

4 G · 4.19 xG · -0.2

012345

BOS finished -1.5 against expected, BUF -0.2.

Source · Backcheck xG model

Shot types · rush and rebound chancesopen +

What they shot — and what went in

Shot diet

goalsshots

BOS

WRIST1/20

SLAP0/8

SNAP0/6

TIP IN0/3

BACKHAND0/3

DEFLECTED0/2

WRAP AROUND0/1

OTHER0/14

BUF

WRIST3/25

SLAP0/6

SNAP1/5

TIP IN0/5

BACKHAND0/3

DEFLECTED0/0

WRAP AROUND0/0

OTHER0/14

BOS

BUF

Off the rush

1 G on 22

1.11 xG

4 G on 27

3.22 xG

Off rebounds

0 G on 6

0.83 xG

0 G on 2

0.26 xG

Wrist shots carried the volume: BOS went 1-for-20, BUF 3-for-25. BUF scored 4 of theirs off the rush.

Source · Backcheck xG model · NHL shot types

New to these numbers?

Two things happened in this game: who created the better chances, and who put the puck in the net. They are not the same thing, and this page separates them on purpose.

The one to watch is expected goals— the best single read on who deserved to win. When it disagrees with the scoreboard, that disagreement is usually the story. Nothing here is a projection; every figure is computed from this game's play-by-play. Full glossary →

xG: Expected goals. Every shot scored by how often that exact look goes in. 2.5 xG means the chances were worth about two and a half goals.
HD: High-danger chances — shots from the slot and the crease, where shots actually become goals.
Corsi: Every shot attempt, including the ones that missed or got blocked. A rough read on who had the puck.
Adj.: Score-adjusted. Teams that trail shoot more and teams that lead sit back, so this corrects the attempt count for the scoreboard.
GSAx: Goals saved above expected. A positive number means the goalie stopped more than an average goalie would have on those shots.
PDO: Shooting % plus save % — a luck gauge. It sits near 1.000 over a season, so a game far from it usually means the bounces decided it.

Shot by shot

In the net

Graded on goals saved above expected

J. Korpisalo

BOS · 30/33 · .909

+1.2

saved above expected

B+

the night

By dangerG/attxGsaved

High danger1/62.0+1.0

Medium1/141.6+0.6

Low2/380.6-1.4

A+ ≥ +2.5 saved above expected · A ≥ +1.5 · B+ ≥ +0.75 · B ≥ +0.25 · C ≥ −0.25 · D ≥ −0.75 · F below −1.5

U. Luukkonen

BUF · 22/23 · .957

+1.5

saved above expected

the night

By dangerG/attxGsaved

High danger0/20.4+0.4

Medium0/151.5+1.5

Low1/400.6-0.4

A+ ≥ +2.5 saved above expected · A ≥ +1.5 · B+ ≥ +0.75 · B ≥ +0.25 · C ≥ −0.25 · D ≥ −0.75 · F below −1.5

87 shots · press play to watch the game back

Where the shots came from

NHL play-by-play coordinates

BOS

43 shots

Final

87 shots

BUF

44 shots

BOS BUF GoalBigger dot · more dangerous look

Each club shoots toward its own end — BOS left, BUF right — the way you would watch it. A dot's size is how dangerous the look was, from distance and angle; it is a proxy for shot quality, not the xG model the article is written from. Hover a dot for the shooter and the clock.

Ranked from the box score

Three stars

Points first

Three stars · computed, not voted

M. Samuelsson

#23 · D · BUF

1 G · 2 A · 2 SOG · 24:56 on ice · +3

T. Thompson

#72 · C · BUF

0 G · 2 A · 4 SOG · 17:55 on ice · +2

P. Krebs

#19 · C · BUF

1 G · 1 A · 1 SOG · 16:28 on ice · +2

Ranked from the box score — points first · Backcheck

What the model said beforehand

Before the game

Written Sat, Dec 27

Open the pre-game read

Written from the numbers

The read

Edited for clarity

◆ By the ModelJul 11, 9:52 PMEdited for clarityDrafted from NHL play-by-play by Backcheck's model, worded for clarity by an AI editor that may not change a number. Nobody at Backcheck was at the rink. How this works

The model gives Buffalo a 55% win probability with an expected scoreline around 2.5 to 2.7 for Boston — barely distinguishable from a flip of the coin.

The Sabres have earned that slight edge through superior underlying play. Buffalo's 5v5 expected goals rate sits at 50.0% to Boston's 47.0%, a difference that compounds over 60 minutes. Corsi%, meanwhile, is dead even at 49.0% for both teams, suggesting the puck possession battle will offer no edge either way.

Both clubs are running hot on PDO. Boston's sits at 1.023; Buffalo's at 1.020. These margins are thin — we're talking about teams getting marginally luckier than their process deserves — but regression is coming for both. The Bruins shouldn't expect this efficiency to hold. Neither should the Sabres.

For Boston, Viktor Arvidsson is the production engine. He's at 1.04 expected goals per 60 minutes with 18 goals and 24 assists, including 2 high-danger chances converted. His 13.0% shooting rate suggests that efficiency can compress; the Sabres' best defensive option is to crowd him. Tanner Jeannot operates at a more modest 0.75 xG/60 but has found 6 goals on just 8.3% shooting — click-click territory, meaning fewer Grade-A looks are going in going forward.

Buffalo counters with Jason Zucker, who's been the more dangerous forward on a per-60 basis. Zucker sits at 1.07 xG/60 with 14 goals, 14 assists, and 6 high-danger goals — that last figure is outlier territory. Josh Doan rounds out the offensive picture at 1.01 xG/60 with 15 goals and 18 assists, though just 2 of those came from high-danger chances.

Both teams face a tactical problem: neither is profiting from high-danger scoring or rebounds. Boston's 0% rate in both categories mirrors Buffalo's 0%, which means both offenses are leaving efficient opportunities on the ice. That inefficiency — if it stays in place — dampens what should be productive nights from these rosters.

Defensively, the Bruins will need to cover Elias Lindholm, who represents a soft spot. Buffalo's weakness is Jack Quinn, a comparable liability on the back end. Whichever team isolates their opponent's weaker link first could create the margin.

Close matchups don't often produce clean predictions. This one fits that mold: two teams generating similar play (Corsi), with Buffalo slightly superior in quality (xG%), both running into variance that's due to reset, and rosters talented enough that a single breakdown on defense could decide the outcome. The Sabres' edge is real but small.

What the model said beforehand

The model's lean

BUF 55%

55%

BUF

Model favorite

45%

55%

BOS50BUF

BUF by 10 points of win probability — a modest lean. Projected score BOS 2.5–2.7 BUF; 18% chance it's tied after 60.

Source · Backcheck Poisson projection · season scoring rates

Season rates · 5v5

Tale of the tape

NHL stats API · our xG

BOS← edge

edge →BUF

47.0%50.0%

49.0%49.0%

2.392.55

2.672.55

2.222.35

1.821.90

1.0231.020

BUF holds 5 of 6 process categories — and the luck row (1.023 vs 1.020) says BOS has been getting the bounces, which tends not to last.

Source · NHL stats API + our xG · 5v5

Form · No games yet

BOS

0-0-0

+0 GD · 0d rest

BUF

0-0-0

+0 GD · 0d rest

1.023

BOS PDO

Luck gauge · drifts to 1.000

1.020

BUF PDO

Luck gauge · drifts to 1.000

What decides it

Keys to the game

Where the edges live

The Sabres own the underlying play — 50.0% 5v5 xG vs 47.0%.

Regression watch

The Sabres' PDO is 1.020 — running hot, expect some regression.
The Bruins' PDO is 1.023 — running hot, expect some regression.

Things to watch

The Sabres own the underlying play — 50.0% 5v5 xG vs 47.0%.
The Sabres' PDO is 1.020 — running hot, expect some regression.

Computed danger · scouting

Players to watch

NHL stats API · our xG

BOS

Viktor Arvidsson18G 24A

1.04 xG/60 · 2 HD · 13.0% sh

Tanner Jeannot6G 14A

0.75 xG/60 · 2 HD · 8.3% sh

BUF

Jason Zucker14G 14A

1.07 xG/60 · 6 HD · 15.1% sh

Josh Doan15G 18A

1.01 xG/60 · 2 HD · 11.5% sh

Keep going

Where to next

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