Something along these lines:
18-19-20-21: 100% capacity
22-23-24-25: 50% capacity
26-27-28-29: 20% capacity
30-31-32: 10% capacity
33-34: 5% capacity
Anti-powertraining cap:
150% if 3 stars or less
125% if 4 stars
100% if 5 stars
75% if 6 stars
50% if 7 stars
25% if 8 stars or more
Doesn't work. The game *sees* the skill points to prevent you from power training.