Always Subbing is the broad team principle of cycling fresh players through possession to keep legs fresh, tempo high, and defensive line speed honest across a full match. It is not a strike play. It is not a fixed starting shape. It is a way of playing.
The system is strike-agnostic. The point is rotation, tempo, and fresh legs — not designing an overlap on a specific touch. If a strike opportunity appears, take it; but Always Subbing's job is finished as soon as a fresh player has cleanly replaced a tired one without breaking the attack.
During possession, the team biases the direction of play toward the sub box side so that touched players have somewhere to exit. A player drops off the field only when they are touched near the sub box or sideline, where the replacement can step on cleanly. Random central exits are not part of the system.
The sub box side depends on the venue. The system should not be hard-coded left or right. The rule is: identify the sub box side, then bias possession toward it.