Look at the action before the touch
IFAB Law 11 distinguishes a deflection from an opponent’s deliberate play; a deliberate save is treated separately. Deliberate play involves control with a possibility of passing, possessing or clearing. A poor result does not automatically make an intentional, controlled attempt a deflection.
Consider two invented clips. In one, a hard pass strikes the outside of a defender’s leg at close range. In the other, a defender watches a slowly arriving ball, sets their feet and tries to pass, but slices it towards an attacker. The final direction looks similar. The preparation and opportunity to control the ball differ.
Replay questions that help
Watch the ball’s journey to the defender before concentrating on the receiving attacker. Was there time to react? Was the direction expected? Did the defender coordinate a pass or merely stretch into the path? Those observations support interpretation; a replay does not reveal an official’s complete reasoning by itself.
The useful distinction is not whether the defender wanted that exact outcome. A mistaken clearance can still involve deliberate play. Conversely, simply making contact does not erase the earlier offside position. This explains why two apparently identical final passes can produce different decisions.
Questions answered
Does every defensive touch make an attacker onside?
No; the nature of that touch matters.
Does an inaccurate clearance necessarily count as a deflection?
No; the attempted action can still be deliberate play.
Sources & further reading
Official references for the subjects discussed. Service terms and device software can change.