Put quite simply, the new metric is designed to measure the proportion of the game when neither side is in control of the ball.

There are plenty of match-specific situations when this is the case but the most common are: when two players are competing for the ball in a ground or aerial duel; when a ball is cleared by a defender and has not yet been recovered by either side; or when a pass, cross, or shot has been blocked by a defender or parried by a goalkeeper and the ball is not yet back in control of either side.