Motion-blurred skater in a gold and black sweater

Breakdown · BOS at CHI

Bruins pull away from the Blackhawks

FinalSat, Jan 17

BOSBoston Bruins5 CHIChicago Blackhawks2

The verdict · earned

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

BOS 5 · CHI 2

◆ By the ModelJul 12, 1:46 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

Expected goals predicted a close game. Boston 3.08, Chicago 2.60. The 5-2 scoreline disagreed.

Goaltending variance drove the gap. A. Soderblom (Chicago) allowed 1.92 more goals than expected, finishing 18/23 with a 0.783 save percentage. J. Korpisalo (Boston) moved in the opposite direction: 22/24 saves, 0.917 save percentage, +0.60 versus expectation. Boston overperformed their xG by 1.92 overall.

The chance quality barely differed. High-danger splits went 5–6, and Boston's xG per shot (0.064) beat Chicago's (0.046). But execution diverged sharply. Chicago scored zero goals on five high-danger chances. Korpisalo saved all five high-danger shots he faced. Boston also scored twice from low-danger areas.

Rush-chance shooting mirrored the pattern: Chicago 2 goals on 25 attempts, Boston 4 on 25. That's the story when underlying metrics suggested parity.

The third period turned on Marat Khusnutdinov's snap shot from the slot.

The breakdown in twelve frames

Swipe it

Every number is from this page

Final · Jan 17

BOS

CHI

Bruins pull away from the Blackhawks

Chances 3.1 – 2.6Did they deserve it? →

Did they deserve it?

The Bruins earned this one.

Expected goals · chance value

BOS

3.08

CHI

2.60

54% of the chances46%

The board read BOS 5, CHI 2. The chances read BOS 3.1, CHI 2.6.

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

Luck check

BOS

+1.9

goals above expected

BOS3.08 expected · 5 scored

Expected

Scored

CHI2.60 expected · 2 scored

Expected

Scored

The Bruins scored 1.9 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 16:14CHIR. Greene0–1
P1 18:14CHIW. Kaiser0–2
P2 01:55BOSC. McAvoy1–2
P2 14:51BOSM. Lohrei2–2
P2 19:14BOSV. Arvidsson3–2
P3 09:01BOSM. LohreiPP4–2
P3 11:02BOSM. Khusnutdinov5–2

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

Where the shots came from

BOS

37 shots

Final

80 shots

CHI

43 shots

BOS CHI GoalBigger dot · more dangerous look

shots · 5 in

shots · 2 in

Every unblocked shot · press play to replay it

Chances by danger

BOSCHI

2 / 6

1.43 xG

High danger

0 / 5

1.01 xG

1 / 9

1.00 xG

Medium

1 / 8

0.86 xG

2 / 33

0.65 xG

Low

1 / 44

0.73 xG

The Blackhawks went 0 for 5 from the slot.

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

In the net

J. Korpisalo

+0.6

BOS · 22/24

A. Soderblom

−1.9

CHI · 18/23

The numbers, checked

BACKCHECK

Bruins pull away from the Blackhawks

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 8–6

16:14CHIR. Greene(A. Burakovsky, C. Bedard)0–1
18:14CHIW. Kaiser(N. Foligno)0–2

2ndshots 9–8

01:55BOSC. McAvoy(E. Lindholm, D. Pastrnak)1–2
14:51BOSM. Lohrei(H. Lindholm, P. Zacha)2–2
19:14BOSV. Arvidsson(P. Zacha, C. Mittelstadt)3–2

3rdshots 6–10

09:01BOSM. Lohreipower play(F. Minten, C. Mittelstadt)4–2
11:02BOSM. Khusnutdinov(D. Pastrnak, E. Lindholm)5–2

score reads BOS–CHI

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

Process vs result

The numbers

XGBoost xG · NHL play-by-play

3.08

BOS chances

Goals their shots were worth

+1.9

Finishing

Goals above what those chances were worth

1.069

BOS puck luck

Above 1.000 — the bounces went their way

45.7%

Shot attempts

Under half — they were outshot

Split by club

Who controlled the game

3.08Expected goals2.60

BOS 54% of the chance quality

23Shots on goal24

6High-danger chances5

48All attempts (Corsi)57

Adjusted for score: BOS 45% · CHI 55%

Faceoffs · CHI won43%off59%neu41%def

Source · NHL play-by-play · XGBoost xG

How the game was won

The danger ladder

shotsgoalsexpected

High dangerslot & crease

BOS2 / 6 · 1.43 xG

CHI0 / 5 · 1.01 xG

Medium dangermid-range

BOS1 / 9 · 1.00 xG

CHI1 / 8 · 0.86 xG

Low dangerperimeter & point

BOS2 / 33 · 0.65 xG

CHI1 / 44 · 0.73 xG

BOS went 2-for-33 from low danger on 0.65 expected goals — 1.4 above expected.

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

The luck layer

Finishing vs expected

expectedactual

BOS

5 G · 3.08 xG · +1.9

CHI

2 G · 2.60 xG · -0.6

0123456

BOS finished +1.9 against expected, CHI -0.6.

Source · Backcheck xG model

Shot types · rush and rebound chancesopen +

What they shot — and what went in

Shot diet

goalsshots

BOS

WRIST3/20

SLAP0/6

TIP IN0/1

SNAP2/6

BACKHAND0/3

DEFLECTED0/1

BAT0/0

OTHER0/11

CHI

WRIST2/30

SLAP0/3

TIP IN0/6

SNAP0/0

BACKHAND0/1

DEFLECTED0/2

BAT0/1

OTHER0/14

BOS

CHI

Off the rush

4 G on 25

2.32 xG

2 G on 25

1.47 xG

Off rebounds

0 G on 2

0.34 xG

0 G on 4

0.61 xG

Wrist shots carried the volume: BOS went 3-for-20, CHI 2-for-30. BOS 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 · 22/24 · .917

+0.6

saved above expected

the night

By dangerG/attxGsaved

High danger0/51.0+1.0

Medium1/80.9-0.1

Low1/440.7-0.3

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

A. Soderblom

CHI · 18/23 · .783

-1.9

saved above expected

the night

By dangerG/attxGsaved

High danger2/61.4-0.6

Medium1/91.0+0.0

Low2/330.7-1.4

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

80 shots · press play to watch the game back

Where the shots came from

NHL play-by-play coordinates

BOS

37 shots

Final

80 shots

CHI

43 shots

BOS CHI GoalBigger dot · more dangerous look

Each club shoots toward its own end — BOS left, CHI 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

0 G · 2 A · 1 SOG · 20:47 on ice · +2

E. Lindholm

#28 · C · BOS

0 G · 2 A · 1 SOG · 18:28 on ice · +2

M. Lohrei

#6 · D · BOS

2 G · 0 A · 3 SOG · 17:21 on ice

Ranked from the box score — points first · Backcheck

What the model said beforehand

Before the game

Written Sat, Jan 17

Open the pre-game read

Written from the numbers

The read

Edited for clarity

◆ By the ModelJul 12, 1:20 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 backs the headline: Boston gets 2.7 expected goals to Chicago's 2.5, and the Bruins earn just 52% win probability—the thinnest possible edge.

Boston owns the underlying play. The Bruins generate 47.0% of shot quality at 5v5 and control 49.0% of shot volume (Corsi), compared to Chicago's 42.0% and 46.0% respectively. They should win this game in a vacuum.

But the Bruins' PDO of 1.023 is a flashing warning. They're converting at 2.7 percentage points above the long-term average—unsustainable luck that will regress. Chicago, running at 0.996, sits right on the line between normal and cold. That PDO gap is the entire reason this game isn't a Bruins W.

Watch the goaltending situation. Both S. Knight and J. Swayman are on back-to-backs, which often means backup play or tired starters. Whichever team gets fresher goaltending gains an edge the underlying metrics miss.

Players to Watch

Boston: Viktor Arvidsson (1.04 xG/60, 18G, 2 HD goals, 13.0% shooting), Tanner Jeannot (0.75 xG/60, 6G, 2 HD goals, 8.3% shooting)

Chicago: Tyler Bertuzzi (0.85 xG/60, 20G, 7 HD goals, 18.0% shooting), Connor Bedard (0.82 xG/60, 17G, 5 HD goals, 11.8% shooting)

Chicago's path is to exploit Boston's defensive weak link, Elias Lindholm, and cash in on high-danger chances. Boston's path is symmetrical—target Anton Frondell and force mistakes on Chicago's back end. Arvidsson and Bertuzzi, both elite finishers, will determine whether the better underlying play translates to two points or none.

The projection says pick a side at random. The PDO discrepancy suggests Boston at a discount. But on a back-to-back goaltending day, discount enough.

What the model said beforehand

The model's lean

BOS 52%

52%

BOS

Model favorite

52%

48%

BOS50CHI

BOS by 4 points of win probability — effectively a coin flip. Projected score BOS 2.7–2.5 CHI; 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 →CHI

47.0%42.0%

49.0%46.0%

2.392.17

2.672.94

2.221.84

1.822.41

1.0230.996

BOS holds 6 of 6 process categories — and the luck row (1.023 vs 0.996) says BOS has been getting the bounces, which tends not to last.

Source · NHL stats API + our xG · 5v5

Form · Last 10

BOS

7-2-1

+15 GD · 1d rest

CHI

5-4-1

-4 GD · 1d rest

1.023

BOS PDO

Luck gauge · drifts to 1.000

0.996

CHI PDO

Luck gauge · drifts to 1.000

What decides it

Keys to the game

Where the edges live

The Bruins own the underlying play — 47.0% 5v5 xG vs 42.0%.

Regression watch

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

Things to watch

The Bruins own the underlying play — 47.0% 5v5 xG vs 42.0%.
S. Knight is on a back-to-back — watch for a backup start or a tired starter.
J. Swayman is on a back-to-back — watch for a backup start or a tired starter.
The Bruins' PDO is 1.023 — 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.929 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.

CHI

Expected in goal

S. Knight

back-to-back.909 last start

Backup Spencer Knight · +10.9 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.

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

CHI

Tyler Bertuzzi20G 15A

0.85 xG/60 · 7 HD · 18.0% sh

Connor Bedard17G 27A

0.82 xG/60 · 5 HD · 11.8% sh

Keep going

Where to next

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