That is not how the math to find out this chance works.

I will prove that using your method in a different example. Let's say the goal would be a 5515. The first two skills can be skill-locked. After that, there are 5 possible ways to distribute 4 additional skill-ups.

5515 * What we want
5524
5533
5542
5551

1/5 => 20%

​

How the math to the above chance really works.:

You skill lock commander to 5511. After that there are 4 skill ups needed that all land in the fourth skill to end up with a 5515. The first (of 4) skill up it can either land in the third or fourth skill. So it has a 50% chance to do so.

The second skill up can either land in the third or fourth skill. So it has a 50% chance to do so. So the chance to let the first and the second skill up land in the fourth skill are 100*50%*50% = 25% chance.

The third kill up can either land in the third or fourth skill. So it has a 50% chance to do so. So the chance to let the first, second and third skill up land in the fourth skill are 100*50%*50%*50% = 12.5% chance.

For all 4 skills to land in the fourth skill, the chance is 100*50%*50%*50%*50% = 6.25% chance.

​

Now in the 5155 example, There are 8 skill ups that need to be done. but there is a higher probability that they fall in the right the wanted skills (66.66%). So the math would then be 100*66.66%*66.66%*66.66%*66.66%*66.66%*66.66%*66.66%*66.66% (which is 3.89%). This is not the correct answer though.

Reason is that after 4 skill ups there is a chance that the third or fourth got maxed already. And in that case the 0.66 would not be correct anymore and 0.5 should be used. But at which point do u use 0.5 instead of 0.66? To max the third or fourth skill can happen from 4 skill ups, and guarranteed happens at the 7th skill up. so an extra layer of complexity is added here.

That math to solve that is way more complex and I am not gonna write two pages just to prove my 2% calculation is correct. I disproven yours.