Motion-blurred skater in a Utah Mammoth sweater

Breakdown · UTA at BUF

Mammoth run the Sabres off the ice on the underlying numbers

FinalSat, Oct 10

The verdict · earned

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

UTA 4 · BUF 1

◆ By the ModelOct 10, 9:48 PMxG: xgboost-0.765Edited 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 Mammoth beat the Sabres 4-1 after T. Thompson opened the scoring on the power play. K. Yamamoto tied it within minutes, then N. Schmaltz and A. Lee pulled the Mammoth clear in the second period. J. Marino finished it on the power play early in the third.

The score and the chances part ways most sharply on finishing. Expected goals measures how many goals a team's chances should have produced. The Sabres' chances were worth 2.94 expected goals, and they scored once. That left them 1.94 goals short of what their chances should have produced.

The Mammoth controlled the game underneath the score, holding 63% of even-strength expected goals. The Sabres held 44% of shot attempts, so Buffalo's problem was not getting shots off.

K. Vejmelka stole the show in goal, posting a .958 save percentage. Utah's attack was just as sharp off the rush. The Mammoth were lethal there, and their 35 rush chances did the damage. Two of their four goals came on the power play.

The turning point was J. Marino's slap shot from the point early in the third, a 4-1 power-play goal. The model rated that shot at only a 4% chance.

Three stars

#6 J. Marino (UTA): 1 goal, 1 assist in 19:06
#27 B. Hayton (UTA): 2 assists in 12:30
#56 K. Yamamoto (UTA): 1 goal, 1 assist in 12:28

What the numbers can't tell you is whether the finishing was luck or skill, why the benches were run the way they were, who was hurt, or what was said in the room. That is the beat's story, and it is worth reading.

Data: NHL play-by-play and shift charts, Backcheck expected goals model

The goals

BUF 0–1, 08:00 of the first on the power play. T. Thompson, wrist shot from 22 feet, an 11% chance by the model (off the rush), past K. Vejmelka. Assists: R. Dahlin. Win probability moved 15 points.
UTA 1–1, 10:12 of the first. K. Yamamoto, wrist shot from 2 feet, an 82% chance by the model, past C. Ellis. Assists: B. Hayton, M. Sergachev. 4 seconds after a UTA missed shot by M. Sergachev. Win probability moved 15 points.
UTA 2–1, 15:23 of the second on the power play. N. Schmaltz, wrist shot from 9 feet, a 14% chance by the model (off the rush), past C. Ellis. Assists: L. Cooley, C. Keller. Win probability moved 24 points.
UTA 3–1, 17:24 of the second. A. Lee, backhander from 7 feet, a 20% chance by the model (off the rush), past C. Ellis. Assists: J. Marino, K. Yamamoto. Win probability moved 16 points.
UTA 4–1, 01:45 of the third on the power play. J. Marino, slap shot from 53 feet, a 5% chance by the model, past C. Ellis. Assists: B. Hayton, A. Lee. Win probability moved 7 points.

The breakdown in twelve frames

Swipe it

Every number is from this page

Final · Oct 10

UTA

BUF

Mammoth run the Sabres off the ice on the underlying numbers

Chances 5.0 – 2.9Did they deserve it? →

Did they deserve it?

The Mammoth earned this one.

Expected goals · chance value

UTA

5.03

BUF

2.94

63% of the chances37%

The board read UTA 4, BUF 1. The chances read UTA 5.0, BUF 2.9.

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

Luck check

UTA

−1.0

goals above expected

UTA5.03 expected · 4 scored

Expected

Scored

BUF2.94 expected · 1 scored

Expected

Scored

The Sabres left 1.9 goals on the table against what their chances were worth.

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

The swing

+24

win-probability points

47% → 71% for UTA

BUF 100%the game, start to finish

UTA 100%P1 · P2 · P3

UTAP2 15:23 · PP

N. Schmaltz makes it 2–1.

In-game win model · fitted on 5,248 games

Every goal, in order

P1 08:00BUFT. ThompsonPP11%0–1
P1 10:12UTAK. Yamamoto82%1–1
P2 15:23UTAN. SchmaltzPP14%2–1
P2 17:24UTAA. Lee20%3–1
P3 01:45UTAJ. MarinoPP5%4–1

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

Where the shots came from

UTA

56 shots

Final

95 shots

BUF

39 shots

UTA BUF GoalBigger dot · more dangerous look

shots · 4 in

shots · 1 in

Every unblocked shot · press play to replay it

Chances by danger

UTABUF

2 / 6

1.90 xG

High danger

0 / 4

0.92 xG

1 / 25

2.65 xG

Medium

1 / 16

1.69 xG

1 / 44

0.47 xG

Low

0 / 42

0.33 xG

The Sabres went 0 for 4 from the slot.

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

In the net

K. Vejmelka

+1.9

UTA · 23/24 · 59:54

Best save · a 32% chance, wrist from 4 ft · P3 07:56

B+

C. Ellis

+1.0

BUF · 26/30 · 59:28

Best save · a 32% chance, snap from 8 ft · P3 12:08

Best skater on the ice

A+

UTA

A. Lee

L · impact 2.48

12:08

Ice time

1–1

G – A

1.25

Own xG

86%

xG share

Impact · top 4

A. Lee2.5A+

J. Marino2.8A+

K. Yamamoto2.2A+

B. Hayton2.0A

Report card

UTABUF

OffenseA+B-

DefenseD+F

TransitionAF

Special teamsAB

GoaltendingAB

DisciplineFA

LuckB-D+

Seven dimensions, A+ to F · basis on the breakdown

Why it went the way it went

Why UTA won

01Dangerous off the rush
02K. Vejmelka tilted the crease
03Won on the merits

Why BUF lost

01Rush defense leaked all night
02Cold finishing night
03Rebound control was shaky

Our storyline model · reasoning on the breakdown

The numbers, checked

BACKCHECK

Mammoth run the Sabres 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 / 12 · Final

Every goal, in order

How it happened

NHL play-by-play

1stshots 12–7

08:00BUFT. Thompsonpower play(R. Dahlin)0–1
Wrist shot from 22 feet, an 11% chance (off the rush), past K. Vejmelka. Win probability moved 15 points.On the ice: M. Samuelsson, R. Dahlin, J. Doan, N. Ostlund, Z. Benson · against N. Schmidt, N. Schmaltz, L. Crouse, J. Marino, C. Keller
10:12UTAK. Yamamoto(B. Hayton, M. Sergachev)1–1
Wrist shot from 2 feet, an 82% chance, a near-certain one, past C. Ellis. 4s after a UTA miss by M. Sergachev. Win probability moved 15 points.On the ice: N. Schmidt, J. Marino, K. Stenlund, J. McBain, D. But · against L. Crevier, J. Doan, N. Ostlund, Z. Benson, Z. Metsa

2ndshots 8–4

15:23UTAN. Schmaltzpower play(L. Cooley, C. Keller)2–1
Wrist shot from 9 feet, a 14% chance (off the rush), past C. Ellis. Win probability moved 24 points.On the ice: N. Schmidt, J. Marino, K. Stenlund, J. McBain, D. But · against R. Dahlin, J. Doan, O. Zellweger, N. Ostlund, Z. Benson
17:24UTAA. Lee(J. Marino, K. Yamamoto)3–1
Backhander from 7 feet, a 20% chance (off the rush), past C. Ellis. Win probability moved 16 points.On the ice: V. Trocheck, M. Weegar, M. Sergachev, D. Guenther, L. Cooley · against T. Thompson, J. Norris, R. Dahlin, J. Quinn, O. Zellweger

3rdshots 10–13

01:45UTAJ. Marinopower play(B. Hayton, A. Lee)4–1
Slap shot from 53 feet, a 5% chance, a shot that rarely goes in, past C. Ellis. Win probability moved 7 points.On the ice: N. Schmidt, K. Stenlund, A. Peeke, J. McBain, D. But · against T. Thompson, J. Norris, R. Dahlin, J. Quinn, O. Power

score reads UTA–BUF

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

Process vs result

The numbers

XGBoost xG · NHL play-by-play

5.03

UTA chances

Goals their shots were worth

−1.0

Finishing

Goals below what those chances were worth

1.037

UTA puck luck

Above 1.000 — the bounces went their way

54.7%

Shot attempts

Over half — they had the puck more

Split by club

Who controlled the game

5.03Expected goals2.94

UTA 63% of the chance quality

30Shots on goal24

6High-danger chances4

75All attempts (Corsi)62

Adjusted for score: UTA 52% · BUF 49%

Faceoffs · BUF won38%off50%neu54%def

Source · NHL play-by-play · XGBoost xG

How the game was won

The danger ladder

shotsgoalsexpected

High dangerslot & crease

UTA2 / 6 · 1.90 xG

BUF0 / 4 · 0.92 xG

Medium dangermid-range

UTA1 / 25 · 2.65 xG

BUF1 / 16 · 1.69 xG

Low dangerperimeter & point

UTA1 / 44 · 0.47 xG

BUF0 / 42 · 0.33 xG

UTA went 1-for-25 from medium danger on 2.65 expected goals — 1.6 left on the table.

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

The luck layer

Finishing vs expected

expectedactual

UTA

4 G · 5.03 xG · -1.0

BUF

1 G · 2.94 xG · -1.9

0123456

UTA finished -1.0 against expected, BUF -1.9.

Source · Backcheck xG model

Shot types · rush and rebound chancesopen +

What they shot — and what went in

Shot diet

goalsshots

UTA

WRIST2/12

SNAP0/25

TIP IN0/7

SLAP1/6

BACKHAND1/6

BETWEEN LEGS0/0

OTHER0/19

BUF

WRIST1/28

SNAP0/2

TIP IN0/4

SLAP0/4

BACKHAND0/0

BETWEEN LEGS0/1

OTHER0/23

UTA

BUF

Off the rush

2 G on 35

3.35 xG

1 G on 25

2.07 xG

Off rebounds

0 G on 6

0.47 xG

0 G on 2

0.43 xG

Wrist shots carried the volume: UTA went 2-for-12, BUF 1-for-28. UTA scored 2 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

K. Vejmelka

UTA · 23/24 · .958

started · 59:54 · win

+1.9

saved above expected

the night

Attempts faced: 39
Avg chance faced: 7.5%
Stopped vs expected: 0.974 vs 0.925
Rebounds allowed: 2

By dangerG/attxGsaved

High danger0/40.9+0.9

Medium1/161.7+0.7

Low0/190.3+0.3

Shorthanded1/121.4+0.4

Tips & deflections0/40.3+0.3

The save

32% chance stopped, a wrist from 4 ft · P3 07:56

The one to have back

11% chance went in, a wrist from 22 ft · P1 08:00

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

C. Ellis

BUF · 26/30 · .867

started · 59:28 · loss

+1.0

saved above expected

B+

the night

Attempts faced: 55
Avg chance faced: 9.1%
Stopped vs expected: 0.927 vs 0.909
Rebounds allowed: 6

By dangerG/attxGsaved

High danger2/61.9-0.1

Medium1/252.6+1.6

Low1/240.5-0.5

Shorthanded2/110.9-1.1

Tips & deflections0/70.4+0.4

The save

32% chance stopped, a snap from 8 ft · P3 12:08

The one to have back

5% chance went in, a slap from 53 ft · P3 01:45

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

Every skater who dressed

Who played

Rated on what they produced and how fast

Best skater on the ice by our rating: A. Lee (UTA), 12:08 of ice, 1-1, 86% of the expected goals while he was out.

UTA18 skaters

Skater	TOI	G-A	SOG	ixG	xG%	PD/PT	Impact	/60	Grade
A. LeeL	12:08	1-1	3	1.25	86	0/0	2.48	12.24	A+
J. MarinoD	19:06	1-1	2	0.09	89	0/0	2.83	8.91	A+
K. YamamotoR	12:28	1-1	2	0.94	84	0/0	2.20	10.60	A+
B. HaytonC	12:30	0-2	1	0.07	66	0/0	1.97	9.46	A
N. SchmaltzC	19:12	1-0	4	0.79	56	1/0	1.59	4.97	A
C. KellerR	18:06	0-1	2	0.23	75	1/0	1.18	3.92	A
D. ButL	10:29	0-0	2	0.15	92	0/0	0.89	5.08	A
M. SergachevD	25:23	0-1	3	0.21	52	1/0	1.17	2.77	B
D. GuentherR	17:18	0-0	5	0.50	71	0/0	0.87	3.00	B
L. CooleyC	20:07	0-1	0	0.00	58	0/1	0.81	2.43	B
N. SchmidtD	19:37	0-0	1	0.01	71	0/0	0.79	2.42	B
V. TrocheckC	17:15	0-0	0	0.32	73	0/1	0.43	1.51	C
J. McBainC	12:09	0-0	0	0.08	70	0/0	0.38	1.90	C
L. CrouseL	14:57	0-0	1	0.06	46	1/0	0.30	1.20	C
K. StenlundC	13:50	0-0	0	0.00	75	0/1	0.27	1.17	C
M. WeegarD	20:23	0-0	2	0.18	45	1/1	0.29	0.86	C
D. SimashevD	13:25	0-0	2	0.14	49	0/0	0.24	1.06	C
A. PeekeD	15:19	0-0	0	0.01	45	0/1	-0.13	-0.50	D

BUF18 skaters

Skater	TOI	G-A	SOG	ixG	xG%	PD/PT	Impact	/60	Grade
R. DahlinD	25:42	0-1	4	0.29	57	0/0	1.54	3.59	A
T. ThompsonC	19:56	1-0	6	0.44	40	0/1	1.02	3.08	B
N. OstlundC	19:08	0-0	5	1.19	48	1/0	0.78	2.44	B
J. QuinnR	20:20	0-0	2	0.34	60	2/1	0.58	1.71	B
P. KrebsC	12:49	0-0	2	0.22	34	1/1	0.07	0.30	C
R. McLeodC	15:27	0-0	0	0.00	46	0/0	-0.07	-0.27	C
J. NorrisC	16:33	0-0	0	0.08	34	0/0	-0.11	-0.38	D
S. CarrickC	8:43	0-0	0	0.00	5	0/0	-0.09	-0.58	D
J. DanforthR	10:15	0-0	0	0.00	30	1/0	-0.14	-0.82	D
Z. BensonL	19:54	0-0	1	0.24	36	0/0	-0.21	-0.64	D
M. SamuelssonD	18:09	0-0	1	0.03	22	0/0	-0.23	-0.76	D
T. KozakC	7:32	0-0	0	0.00	2	0/0	-0.21	-1.67	D
J. DoanR	14:16	0-0	2	0.08	28	0/1	-0.32	-1.33	D
B. MalenstynL	12:11	0-0	0	0.00	1	0/0	-0.30	-1.48	F
Z. MetsaD	12:38	0-0	0	0.00	17	0/0	-0.49	-2.33	F
O. PowerD	25:06	0-0	0	0.01	21	0/1	-0.66	-1.58	F
O. ZellwegerD	18:30	0-0	0	0.01	14	0/1	-0.62	-2.00	F
L. CrevierD	15:07	0-0	1	0.01	14	0/0	-0.70	-2.77	F

xG% = share of expected goals while on the ice · PD/PT = penalties drawn / taken · “in N min” = a per-60 rate far above the raw total. Impact = 0.75 G + 0.7 A1 + 0.55 A2 + 0.075 SOG + 0.05 BLK + 0.15 penalties drawn − 0.15 taken + 0.01 faceoff wins − 0.01 losses + 0.3 individual xG + 0.5 on-ice xG for − 0.5 on-ice xG against. Rating = 65% impact + 35% impact per 60, as a percentile among the skaters in this game.

Scratched, UTA: L. O'Brien, M. Carcone, N. DeSimone. Scratched, BUF: M. Grzelcyk, J. Kulich, K. Helenius. Referees Michael Markovic and Morgan MacPhee; linesmen Scott Cherrey and Tommy Hughes.

Graded against a league-average game

Report card

Seven dimensions · A+ to F

DimensionUTABUF

Offense

▸Basis

UTA Created 5.03 xG against a ~2.70 league-average game; 6 high-danger shots (1.90 xG) and 35 rush shots (3.35 xG).

BUF Created 2.94 xG against a ~2.70 league-average game; 4 high-danger shots (0.92 xG) and 25 rush shots (2.07 xG).

A+

100

B-

Defense

▸Basis

UTA Allowed 2.94 xG against a ~2.70 league-average game; conceded 4 high-danger shots (0.92 xG) and 25 rush shots (2.07 xG).

BUF Allowed 5.03 xG against a ~2.70 league-average game; conceded 6 high-danger shots (1.90 xG) and 35 rush shots (3.35 xG).

D+

Transition

▸Basis

UTA Rush shots 35–25, rush xG 3.35–2.07 (rush-based; public data has no zone entries).

BUF Rush shots 25–35, rush xG 2.07–3.35 (rush-based; public data has no zone entries).

Special teams

▸Basis

UTA 2-for-5 on the power play (40%; league ≈21%) with 0.91 PP xG.

BUF 1-for-4 on the power play (25%; league ≈21%) with 1.14 PP xG.

Goaltending

▸Basis

UTA +1.94 goals saved above expected on 24 shots against.

BUF +1.03 goals saved above expected on 30 shots against.

Discipline

▸Basis

UTA Took 6 penalties for 23 PIM vs 6 for 15 on the other side.

BUF Took 6 penalties for 15 PIM vs 6 for 23 on the other side.

Luck

Grades bounces, not skill — C is neutral

▸Basis

UTA Finishing -1.03 goals vs xG plus +1.94 GSAx of save luck = +0.91 total. This grades luck, not skill — C is neutral, A is very lucky.

BUF Finishing -1.94 goals vs xG plus +1.03 GSAx of save luck = -0.91 total. This grades luck, not skill — C is neutral, A is very lucky.

B-

D+

Source · NHL play-by-play · xG engine · luck graded separately

What the model flagged

WARNINGBUF

Rush defense leaked all night

Gave up 35 rush shots worth 3.35 xG (2 goals) — transition gaps were there every period.

Tighten neutral-zone structure and keep D gaps closed on entries.

STRENGTHUTA

Dangerous off the rush

2 goals on 35 rush shots worth 3.35 xG.

WARNINGUTA

Rush defense leaked all night

Gave up 25 rush shots worth 2.07 xG (1 goals) — transition gaps were there every period.

Tighten neutral-zone structure and keep D gaps closed on entries.

LUCKBUF

Cold finishing night

Scored 1 on 2.94 xG — -1.94 vs expected. The looks were there; the finish will come back.

STRENGTHBUF

Dangerous off the rush

1 goals on 25 rush shots worth 2.07 xG.

STRENGTHUTA

K. Vejmelka tilted the crease

K. Vejmelka stopped 23 of 24 (0.958), +1.94 goals above expected.

95 shots · press play to watch the game back

Where the shots came from

NHL play-by-play coordinates

UTA

56 shots

Final

95 shots

BUF

39 shots

UTA BUF GoalBigger dot · more dangerous look

Each club shoots toward its own end — UTA 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

J. Marino

#6 · D · UTA

1 G · 1 A · 2 SOG · 19:06 on ice · +1

B. Hayton

#27 · C · UTA

0 G · 2 A · 1 SOG · 12:30 on ice · +2

K. Yamamoto

#56 · R · UTA

1 G · 1 A · 2 SOG · 12:28 on ice · +2

Ranked from the box score — points first · Backcheck

Keep going

Where to next

Back to the front page