This rule was not adopted to make things equitable but to make things SAFE! In the 1980's when we started playing this game, we shot bows over 100 pounds and very light, short arrows. You would see eguipment explode at every shoot. Since this was very dangerous the IBO contacted the bow manufactors and asked what grain to pound ratio would be safe. This is where the 5 grains of arrow weight vs each pound of draw weight came from. The short draw folks soon realized their bows would not reach the speeds of the long draw bows because of the difference in the power stroke. The rule was changed to help this problem by allowing the shorter power stroke bows to shoot 280 FPS with lighter than 5 grain per pound arrows. The manufactors felt this was safe because of the shorter power stroke. Hope this helps.