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Breakdown · BOS at BUF

Bruins edge the Sabres in overtime

Final / OTWed, Mar 25

The verdict · stolen

The Bruins stole one. They lost the expected-goals battle 2.40–2.81 and won anyway.

BOS 4 · BUF 3

◆ By the ModelJul 12, 8:49 AMxG: 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

Boston's 4-3 victory masked a game where the underlying numbers favored Buffalo — expected goals went 2.81–2.40 to the Sabres, a 54-46 split that suggested this was their coin toss to win. The Bruins overperformed their xG by 1.60 goals, while Luukkonen underperformed by the same margin.

Boston's J. Korpisalo stopped 22 of 25 shots for a 0.880 save percentage. Luukkonen, absorbing 31 shots, made 27 saves (0.871 SV%).

The Sabres held 45% of shot attempts (25–31 on goal). High-danger chances split evenly at 3–3, but both teams found identical success from the rush: three goals each, Boston on 23 chances and Buffalo on 29. Buffalo weaponized the power play with two goals on nine shots (0.66 xG), while Boston generated higher-quality looks than their shot total suggested.

Pavel Zacha ended it at 00:38 of overtime with a wrist shot from the high slot.

D. Pastrnak (Boston) posted one goal and two assists in 21:56. T. Thompson (Buffalo) recorded two assists in 18:44. J. Zucker (Buffalo) scored twice in 15:58.

The breakdown in twelve frames

Swipe it

Every number is from this page

Final · OT · Mar 25

BOS

BUF

Bruins edge the Sabres in overtime

Chances 2.4 – 2.8Did they deserve it? →

Did they deserve it?

The Sabres deserved better.

Expected goals · chance value

BOS

2.40

BUF

2.81

46% of the chances54%

The board read BOS 4, BUF 3. The chances read BOS 2.4, BUF 2.8.

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

Luck check

BOS

+1.6

goals above expected

BOS2.40 expected · 4 scored

Expected

Scored

BUF2.81 expected · 3 scored

Expected

Scored

The Bruins scored 1.6 more than their chances were worth. That does not repeat.

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

Every goal, in order

P1 11:07BOSD. Pastrnak1–0
P1 15:18BUFJ. ZuckerPP1–1
P2 09:45BOSV. Arvidsson2–1
P3 05:21BUFZ. Benson2–2
P3 05:54BUFJ. ZuckerPP2–3
P3 14:00BOSC. Mittelstadt3–3
OT 00:38BOSP. Zacha4–3

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

Where the shots came from

BOS

45 shots

Final

83 shots

BUF

38 shots

BOS BUF GoalBigger dot · more dangerous look

shots · 4 in

shots · 3 in

Every unblocked shot · press play to replay it

Chances by danger

BOSBUF

0 / 3

0.67 xG

High danger

1 / 3

0.72 xG

3 / 11

1.06 xG

Medium

2 / 12

1.32 xG

1 / 45

0.67 xG

Low

0 / 43

0.76 xG

High-danger looks: BOS 0 of 3, BUF 1 of 3.

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

In the net

J. Korpisalo

−0.2

BOS · 22/25

U. Luukkonen

−1.6

BUF · 27/31

The numbers, checked

BACKCHECK

Bruins edge the Sabres in overtime

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 11–7

11:07BOSD. Pastrnak(F. Minten, M. Khusnutdinov)1–0
15:18BUFJ. Zuckerpower play(T. Thompson, J. Quinn)1–1

2ndshots 13–12

09:45BOSV. Arvidsson(D. Pastrnak, N. Zadorov)2–1

3rdshots 6–6

05:21BUFZ. Benson2–2
05:54BUFJ. Zuckerpower play(T. Thompson)2–3
14:00BOSC. Mittelstadt(J. Aspirot, P. Zacha)3–3

OTshots 1–0

00:38BOSP. Zacha(D. Pastrnak, C. McAvoy)4–3

score reads BOS–BUF

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

Process vs result

The numbers

XGBoost xG · NHL play-by-play

2.40

BOS chances

Goals their shots were worth

+1.6

Finishing

Goals above what those chances were worth

1.016

BOS puck luck

About 1.000 — a normal night for bounces

50.4%

Shot attempts

Over half — they had the puck more

Split by club

Who controlled the game

2.40Expected goals2.81

BUF 54% of the chance quality

31Shots on goal25

3High-danger chances3

59All attempts (Corsi)58

Adjusted for score: BOS 50% · BUF 50%

Faceoffs · BUF won53%off18%neu71%def

Source · NHL play-by-play · XGBoost xG

How the game was won

The danger ladder

shotsgoalsexpected

High dangerslot & crease

BOS0 / 3 · 0.67 xG

BUF1 / 3 · 0.72 xG

Medium dangermid-range

BOS3 / 11 · 1.06 xG

BUF2 / 12 · 1.32 xG

Low dangerperimeter & point

BOS1 / 45 · 0.67 xG

BUF0 / 43 · 0.76 xG

BOS went 3-for-11 from medium danger on 1.06 expected goals — 1.9 above expected.

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

The luck layer

Finishing vs expected

expectedactual

BOS

4 G · 2.40 xG · +1.6

BUF

3 G · 2.81 xG · +0.2

012345

BOS finished +1.6 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

WRIST2/28

SNAP1/9

SLAP0/5

TIP IN0/2

BACKHAND1/1

DEFLECTED0/0

OTHER0/14

BUF

WRIST2/20

SNAP1/4

SLAP0/7

TIP IN0/4

BACKHAND0/2

DEFLECTED0/1

OTHER0/20

BOS

BUF

Off the rush

3 G on 23

1.52 xG

3 G on 29

2.36 xG

Off rebounds

0 G on 2

0.32 xG

0 G on 0

0.00 xG

Wrist shots carried the volume: BOS went 2-for-28, BUF 2-for-20. BOS scored 3 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 · 22/25 · .880

-0.2

saved above expected

the night

By dangerG/attxGsaved

High danger1/30.7-0.3

Medium2/121.3-0.7

Low0/430.8+0.8

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 · 27/31 · .871

-1.6

saved above expected

the night

By dangerG/attxGsaved

High danger0/30.7+0.7

Medium3/111.1-1.9

Low1/450.7-0.3

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

83 shots · press play to watch the game back

Where the shots came from

NHL play-by-play coordinates

BOS

45 shots

Final

83 shots

BUF

38 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

D. Pastrnak

#88 · R · BOS

1 G · 2 A · 3 SOG · 21:56 on ice · +3

T. Thompson

#72 · C · BUF

0 G · 2 A · 3 SOG · 18:44 on ice · -1

J. Zucker

#17 · L · BUF

2 G · 0 A · 4 SOG · 15:58 on ice · -1

Ranked from the box score — points first · Backcheck

What the model said beforehand

Before the game

Written Wed, Mar 25

Open the pre-game read

Written from the numbers

The read

Edited for clarity

◆ By the ModelJul 12, 8:48 AMEdited 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 projects a BOS 2.5–2.7 BUF game with the Sabres at 55% win probability—about as close to a pick'em as you'll find.

Buffalo owns the underlying play. The Sabres generate 50.0% of expected goals at 5v5 compared to Boston's 47.0%. Both teams' Corsi percentages sit at 49.0%, but the Sabres' edge in shot quality matters. That advantage in the metrics that predict wins would normally favor Buffalo decisively.

Both teams are running hot in a way that won't persist. The Sabres' PDO of 1.020 and the Bruins' 1.023 both represent outperformance of their underlying numbers. Regression is inevitable for both. Don't mistake recent success for sustainable advantage—it masks how close this game truly is.

Watch J. Swayman's status. The Bruins' goaltender is on a back-to-back; Boston could deploy a backup or ask Swayman to play fatigued. Either scenario disadvantages the Bruins in a game they can't afford to give away.

Players to Watch

BOS: Viktor Arvidsson (1.04 xG/60, 18G 24A, 2 HD goals, 13.0% shooting) generates chances at an elite rate with an elite finish. His shooting percentage is well above sustainable. Tanner Jeannot (0.75 xG/60, 6G 14A, 2 HD goals, 8.3% shooting) is shooting below expectation—a regression waiting to happen.

BUF: Jason Zucker (1.07 xG/60, 14G 14A, 6 HD goals, 15.1% shooting) is Buffalo's most dangerous forward, combining volume and conversion. Josh Doan (1.01 xG/60, 15G 18A, 2 HD goals, 11.5% shooting) is another high-converting threat.

Boston's task is neutralizing Zucker—his chance generation and goal rate form the Sabres' core advantage. Buffalo must contain Arvidsson, whose efficiency will regress but not his output. Elias Lindholm represents Boston's defensive vulnerability; Jack Quinn carries Buffalo's. In a game this close, a breakdown from either defenseman could tip the scale.

The Sabres have the better underlying game. But both teams' unsustainable shooting environments and the Bruins' goaltending uncertainty erase the edge. This is a true coin flip.

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 · Last 10

BOS

5-2-3

+4 GD · 1d rest

BUF

8-1-1

+18 GD · 2d 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%.
J. Swayman is on a back-to-back — watch for a backup start or a tired starter.
The Sabres' PDO is 1.020 — running hot, expect some regression.

Last game's lineup · confirmed at warm-up

Lineups

NHL box score

BOS

Expected in goal

J. Swayman

back-to-back.912 last start

Backup Jeremy Swayman · +28.8 GSAx this season

Back-to-back: the backup often gets this one. Treat the starter as unconfirmed.

No completed game on file for this club yet.

BUF

Expected in goal

A. Lyon

2 days rest.818 last start

Backup Ukko-Pekka Luukkonen · +10.5 GSAx this season

No completed game on file for this club yet.

Lineups are the players who dressed in each club's last game, with their minutes; clubs confirm tonight's at warm-up. Every player this preview names was in that lineup.

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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