Fixture 30scheduledGW 3

Arsenal v Chelsea

Sun 6 Sept 15:30Zmarket prices held

Expected goals1.96 — 0.93

Expected points2.05 — 0.72

Over 2.555.0%fair 1.82

Both score52.5%fair 1.91

Most likely1-110.7%

Markets priced27

Ch 01 · Outcome

Match result

The bar is the model's probability; the caret on the same scale is the market's, with the margin removed. The distance between them is the disagreement.

OutcomeModel fill · market caretProbFairΔ mkt

ARS

60.9%1.64+4.1 pp

Draw

22.5%4.44−2.2 pp

CHE

16.6%6.03−1.9 pp

Ch 02 · Book

27 markets

dixon_coles xi001-20260903

Model fair prices, computed as 1 / probability from a Dixon-Coles score matrix. No bookmaker margin is included, and no bookmaker is quoting these. A real price will be shorter than every number here.

Match result

Arsenal60.9%1.64

Draw22.5%4.44

Chelsea16.6%6.03

Double chance

Arsenal or draw83.4%1.20

Arsenal or Chelsea77.5%1.29

Draw or Chelsea39.1%2.56

Draw no bet

Arsenal78.6%1.27

Chelsea21.4%4.67

A draw returns the stake, so these prices exclude it.

Win to nil

Arsenal33.5%2.99

Chelsea7.9%12.62

Clean sheet

Arsenal39.6%2.52

Chelsea14.1%7.11

Ch 03 · Reasoning

What is driving this

computed, not generated

Computed arithmetic, not generated text. Each driver is a stored quantity: the Elo difference replayed from results, points per game over the last five matches, rolling expected goals, and each absent player's share of team expected goals.

Underlying expected goals+1.17 net xG per match

Favours ARS. ARS +1.32, CHE +0.14 across the form window — results are noisier than the chances behind them

Team rating gap+174 Elo

Favours ARS. ARS 1751 against CHE 1577, computed from stored results; an Elo-driven model scores RPS around 0.2015 on this league against roughly 0.194 for de-vigged closing odds

Recent form3.00 against 2.00 points per game

Favours ARS. last 5 and 5 completed matches: WWWWW against WWLWD

Home advantage+60 Elo equivalent

Favours ARS. the football default is around 100 Elo points, but Premier League home advantage fell during the crowdless 2020/21 season and settled lower afterwards, so the ratings carry a smaller term

Unavailable players0% home against 0% away xG missing

3 out and 0 doubtful for ARS, 0 out and 3 doubtful for CHE; measured as the share of recent expected goals those players contributed

Ch 04 · Comparison

Both sides

ARS

WWWWW

10 May – 31 Aug

CHE

DWLWW

9 May – 30 Aug

3.00Points per game2.00

8Goals for11

1Goals against9

9.94Expected goals9.02

1,751Elo1,577

Head to head over 10 meetings in the seasons held (Premier League from 2021-22, Championship from 2024-25): ARS 6, drawn 3, CHE 1. Cup ties and earlier seasons are not included, so a full-history site will show more.

Ch 05 · Market

Bookmaker prices

Real bookmaker prices, collected from published market data.

Market	Selection	Best	Book	Implied	N
h2h	away	5.40	Smarkets	18.5%	42
h2h	draw	4.00	Betfred (UK)	25.0%	42
h2h	home	1.77	1xBet	56.5%	42

Ch 06 · Availability

Arsenal

0.0% xG out

Share of attacking output is what moves the number, so it is shown rather than implied.

J.TimberDEFinjured0%

Groin injury - Unknown return date

NelsonMIDunavailable0%

has departed the club as a free agent.

SalibaDEFinjured0%

Back injury - Unknown return date

Ch 06 · Availability

Chelsea

0.0% xG out

Share of attacking output is what moves the number, so it is shown rather than implied.

CaicedoMIDdoubtful75%

Unspecified injury - 75% chance of playing

HendersonMIDdoubtful75%

Wrist injury - 75% chance of playing

PalestraDEFdoubtful75%

Unspecified injury - 75% chance of playing

Ch 07 · Simulation

Re-price without a player

Removing a player scales that side's expected goals by their share of recent attacking output, then rebuilds the score matrix. Every market moves together.

Ch 09 · Divergence

Where the model differs from a price

Shown with the model's own record, because that is what decides how much these are worth.

h2h homemodel 60.9% vs 1.77 (1xBet)+7.8 ppstake 2.0%medium confidence

Ch 10 · Calibration

How this model actually scores

Dixon-Coles bivariate Poisson fitted to Premier League results with exponential time decay. Statistical model, no language model involved.

loses to closing market2,281 out-of-sample fixtures

Metric	Model	Market	Δ
Ranked probability score	0.2047	0.1965	+0.0082
Log loss	0.9882	0.9623	+0.0259
Brier	0.5883	0.5711	+0.0172
Accuracy	52.5%	54.8%	−2.3 pp

Lower is better for the first three. These probabilities are for reading a fixture, not for expecting profit against closing prices. What these numbers mean