Defensive Works: While this Formation remains in play, the Shropshire Lane and Sopwell Lane Formations do not suffer more than one hit when Attacked.
Note that this ability is negated whenever the Yorkist Archers Special Formation has a cube on its card.
When this Formation is Routed, the Defensive Works ability is permanently lost.
I know, I know - you want some historical commentary. Warwick snuck around the formidable enemy front-line defenses to capture the King in their rear. Warwick squeezed from his end, Salisbury and York from theirs, with the other guys stuck in the middle, thus negating the enemy's positional advantage.