[Suicide Junkie]

6.4.9 Boarding Party 1, 2, 3, 4, 5 = 20, 40, 60, 80, 100 guys respectively. Security Station 1, 2, 3, 4, 5 = 60, 100, 140, 180, 220 turrets respectively. Any BP or SS takes up 20kt space. Boarding is successful if the boarding parties are greater than the effective number of defenders (Security Stations turrets + 25% of boarding parties on the defending ship used as defenders + 16 for every undestroyed Crew Quarters)

Boarding parties provide FULL defense, not just 25%.