still, and the attackers run to the goal; with the same calculation, the attacking player is 1·25–1·50 m from the last defender when the pass began. When the attacking player is behind the last defender and both run in opposite directions, the difficulty comes from the attacking player running at the defender in the moments before the pass, while the defender moves in the opposite direction at the same speed. In the moment that the ball is passed, all the players involved are in the same line but running in opposite directions. Applying the 250–300 ms time to complete the SEM, the attacking player is located 3·75–4·5 m from the last defender (the sum of the 1·87–2·25 m that the defenders move to the centre of the field and the attackers to the goal.) When the attacking player is located behind the last defender, and running towards him, the attacking player will be 1·87–2·25 m from the defender and the real position that he was in at the exact moment of the start of the ball-pass. FIFA has expected these errors, but without any calculation, and already decided that the AR, when in doubt about an off-side position, should not penalise the attacking player.