Which position would be best to repel an attack to your flank?

The best position to repel an attack to your flank is the supplementary position.

In military tactics, the supplementary position is specifically designated to reinforce or support the primary position. It’s placed in such a way that it can provide additional firepower and tactical advantage against an enemy that maneuvers to attack from the side. In the context of repelling a flank attack, the supplementary position helps to cover vulnerable areas that the primary position may not adequately protect, enhancing the overall defensive capabilities of the unit.

The other positions—primary, alternate, and base—serve different roles. The primary position is the main defensive location that engages the enemy directly, and while it is crucial for overall defense, it may not cover flank attacks effectively on its own. The alternate position is a fallback location that can be used if the primary position is compromised, but it is not actively engaged in the defense of the flank unless necessary. The base position is typically the location where support activities are conducted rather than direct engagement in combat. Hence, the supplementary position is the most directly relevant for addressing an immediate threat to your flank.