How do you calculate %xHKO?

By the way...

its quite easy to calculate

once you have done all the damage calculation and have your
max and minimum damage:

you can have 3 types of values:
worst case scenario = deal minimum damage for all hits
best case sceniaro = deal maximum damage for all hits
normal case scenario = deal average damage for all hits = (maxDamage + minDamage)/2

then find out the monster hp:

assuming that the monster is 9 hp
your max damage is 3
your min damage is 1
your average damage is 2 (maxDamage + minDamage) / 2 = (3+1)/2 = 2

then how many hits to ko monster would be:
maxDamage = 9/3 = 3 hits ko
minDamage = 9/1 = 9 hits ko
averageDamage = 9/2 = 4.5 hits ko

then you add in the probability:

what are the probability of having 3 hits maxDamage/minDamage?
(note: maxDamge would be same as minDamge)

This method doesn't actually work.

If your min damage is 1 and max damage is 3, your average damage is 2. By dividing average damage by 2 HP, you get that your average number of hits is 1.

Clearly this isn't the case - you have a 2/3 chance of 1, and a 1/3 chance of 2.