Articles & guides
Long-form writing on expected goals, shot quality, and the models behind the xG numbers you see on broadcasts. All articles are free and written to be understandable whether you are brand new to football analytics or comfortable reading an academic paper.
What is expected goals (xG)? A complete beginner’s guide
The origin of xG, how it’s calculated, what a “good” xG looks like, common misconceptions, and how to read an xG shot map. If you are starting from zero, start here.
How xG models differ, and why their numbers rarely match
A side-by-side tour of the academic xG models used in this calculator: Rathke’s zone model, the Kos Angle, Anzer & Bauer’s positional model, CNN pixel-based xG, and more. Find out why the same shot gets a different xG from each one.
xG glossary: every football analytics term explained
xA, xT, PSxG, SHAP, ROC-AUC, Kos Angle, shot maps — plain-English definitions of the terms you’ll see in analytics articles, Twitter/X threads and broadcasts.