How does chance work in Pokemon?

Like some people say Fire Fang has a 20% chance to either burn or flinch, but I say its 19% because 1 - (1 - 10/100)(1 - 10/100) = 19%. I still dont know if thats how %s work. But then how does stuff like Crunch 3 times over 3 turns and getting the defense drop 2 times work (chance of that happening)? Thanks :)

Pleaselog inorregisterto add a comment.

Time for a little lesson on probability

To answer this question we need to set a few guidelines

Now the question we are trying to answer is what is the chance that it flinches OR burns, which can be restated as P(A orB)

This is a very simple question when one knows the right formulas, and for this case, it would be the one below

P(A or B)= P(A)+P(B)-P(A and B)

so basically the probability that fire fang flinches or burns IS the chance of it flinching plus the chance of it burning minus the chance of both of them happening, and when plugging in the numbers, this is what you get

Therefore the chance that it both flinches and burns is 19%, your initial intuition was correct! Though I hope this helped you understand why

As for your question on the probability of crunch getting a defense drop 2 times over 3 uses: it is a different type of probability involving a binomial distribution.

To answer the question, we need to set a few guidelines

The Binomial Formula is a bit complicated and I’m sure you are already tired of my math and such but here it is anyways

You will probably ignore that and I won’t blame you!

But if I were to plug it into the formula(which I won’t since I can just use calculator functions ;) then I would get….

0.096(9.6%)

This is the chance that you land two defense drops in three crunches, a surprisingly high probability actually

WELL

hoped I helped