How likely is Head Smash to hit after double Minimize and fog?

So, yesterday, when I was grinding levels on my Onix in the NatDex area of Victory Road, I got in to a double battle. One of the trainers had a blissey, that used minimize twice. The fog weather condition was also in effect. I brought my rampardos, and I used head smash (and didn’t expect it to hit) but it did, and it OHKOd. How likely was that move to hit?

Pleaselog inorregisterto add a comment.

Head smash has 80% accuracy.sourceFog multiplies accuracy by 3/5.source+2 evasion multiplies accuracy by 60%.sourceThe resulting chance to hit is 0.288, or 28.8%.

Head Smash is base accuracy 80%. The fog modifies the accuracy of the move by a factor of 60%, meaning the accuracy is 80% × 60% = 48%.

Minimise being used twice means an evasiveness of +2 (it only raised the evasion by 1 stage in gen 4), which is effectively multiplying the accuracy by 60% yet again. The formula is:

base accuracy × (accuracy - evasiveness)

with any extra effects (e.g. fog) applied to the base accuracy.

The 48% accuracy in addition to ×60% from minimise results in a 28.8% chance to hit. Not so lucky after all, and sumwun was correct.

Source