Using a StatsBomb event based expected goals model with Metrica's tracking data to attribute non-shot-xG to every possession of each team.
Goals, shots and expected goals are only counted if shots are actually taken.
The problem is that there are some chances where a goal is likely but a player doesn’t shoot for some reason, they choose to pass, or hesitate etc.
How do we measure or quantify these Non-Shot chances?
When a shot is taken, that is quantified and tracked in traditional metrics.
When there is no shot in a possession, that is lost. Non-shot expected goals takes the highest expected goal value assuming that the attacking palyer could have taken a shot.
This is NOT saying that the attacking player should always shoot rather than pass to get a better shot, but rather a way to quantify and track post-match.
Karun Singh's Expected Threat concept: Expected Threat
Friends of Tracking and Laurie Shaw's Metrica Tracking Tutorials: Friends of Tracking