To determine the distance of the "flee"-moved the loosing side make, determine it by dividing the CR (Combat Result) by the number of units that where fighting (on the loossing side !!!!!!). So if you win by 15, and originaly where fighting 3 enemy units, of which you "killed" one, the remaining units would move back by 5 cm each --> you get pursuit bonus + 3 cm bonus = +2 att per stand for those stands that follow-up