Let me explain the numbers 20 and 10%. These numbers were chosen so that, firstly, there would be a significant difference between the groups (there is no significant difference between 10 and 12%). And secondly, to make it easier to calculate the chances of acquiring a new skill. For example, at the start, you have a racial +1 base (20%). This means that the chance of getting the primary base is 20/80 (80 = 100-20), and the secondary base is 10/80. If another popular base is acquired, the total will change from 80 to 60 or 70, which is also convenient for calculations (round numbers). If a rare base (2%) is acquired, the number is so small that it can be ignored. That is, I find the option 20*3 + 10*3 + 2*5 to be the most convenient, simple, and intuitive. The racial bonus is set to 0% because it is always present by default from the start.
I did it this way:
3*15 + 3*10 + 3*6 + 3*2 = 99 (1% was assigned to the racial bonus because there was nowhere else to put it).
I did it this way because I don't want it to be impossible to acquire any particular skill – there should be a minimum of 2%. Ideally, I see it as: 3 with a high probability, 6 with a medium probability, and 3 with a low probability; or 4-4-4
Блистает там воздушностью прогалин.
Но между кедров, полных тишиной,
Расщелина по склону ниспадала.
О, никогда под бледною луной
Так пышен не был тот уют лесной...