xG and Expected Goals - Is It Already Priced Into Markets or Is There Still Edge?

[Klaus]

Specific question with a specific timeline that matters.

I started incorporating xG data into the Bundesliga model in 2016.

At that point xG was available to serious analysts but hadn't entered mainstream football discourse. Match of the Day wasn't displaying it. Casual fans had no idea what it was. Operators were incorporating it inconsistently.

The edge I found from xG-based analysis in 2016-2018: meaningful. Teams systematically over or underperforming their expected goals created predictable regression patterns the market hadn't fully priced.

2019 onwards: xG enters mainstream broadcast. Opta and StatsBomb data becomes standard operator infrastructure. The Bundesliga model's xG component produces diminishing returns.

2021-2024: the basic xG regression trade is largely closed in top flight markets.

My question for the forum: does genuine xG edge still exist anywhere, or has the metric been fully absorbed into market pricing.

 

[SharpEddie47]

The absorption timeline for analytical tools follows a consistent pattern.

Academic discovery. Small community of serious analysts using it. Edge exists. Tool becomes commercially available. Operators adopt it. Edge compresses. Tool enters mainstream discourse. Edge largely gone in liquid markets.

xG has followed this pattern precisely.

The NFL equivalent was DVOA and similar efficiency metrics from Football Outsiders. Generated genuine edge when the analytics community was small. By 2015 the major US books had hired the analysts themselves.

The question isn't whether xG has been priced in at the top level. It has.

The question is how far down the leagues the absorption has traveled.

Championship? Probably mostly priced.
League One? Less certain.
National League? Possibly still generating signal.
Comparable leagues in smaller markets? Potentially significant remaining edge.

The tool hasn't been eliminated. The frontier has moved.