i got the same conclusion from my 18 yr old gk. he is 5 star. i assigned some skill points after power training but left him with 1 skill point short of 6 star. i noticed that he has slowed down during training. it's as if the engine is recognizing and adding up the unassigned skilled points. when he was still 5 star, he was getting like 32-40+ for hard stretching. after he became sort of 6 star w/ unassigned skill points, he is getting 20 for hard stretching.