Previously I wrote about replacing the intelligence ability in classic D&D with quickness. This yields three pairs of ability scores...
strength / constitution
dexterity / quickness
charisma / wisdom
In Star Frontiers, ability scores are paired in a similar manner. When generating them, you roll once for each pair, and the same value is applied to each score in the pair. Then the player may adjust them by taking points away from on score in the pair and adding them to the other.
(The AD&D2e book Players Option: Skills & Powers did something similar, though it split the original six ability scores into twelve scores.)
The range of scores is 1–100 (though initial values range from 30—70) and the adjustment is limited to 10 points. So that would translate to 2 points in D&D. e.g. If 12 was rolled for dexterity/quickness, the player could set the scores at 12/12, 13/11, 14/10, 11/13, or 10/14.
I’m not sure that only rolling three scores would be a good thing, though.