How to get an Everstone from the Mauville Inverse Battle stop?

Question

So I'm trying to get an Everstone from the Inverse Battle Stop but I can't seem to do it. All I have gotten are Oran Berries (when I did bad but won), a Colbur Berry (I don't remember how), and Sitrus Berries, which I seem to get for doing really good. I just can't seem to get an Everstone. All that I can find on Bulbapedia is this:

After he is defeated, Inver will give the player an item depending on how well they did.

However, that doesn't help me much. Can someone help me with this?

Answer 1

Inver's evaluation of the player is based on a score calculated by subtracting the number of not very effective hits the player made from the number of super effective hits they made.

You need to score between a seven and a nine to get an Everstone, but there's also a chance to get all of the other evolutionary stones. Assuming the chance of getting each of them is equal, you've only got a 10% chance of getting one, assuming you score between seven and nine. That combined with the fact that you can only battle him once a day, you'd be much better off using a different method to get an Everstone.

Source

Comments

Okay I think I get how to do the Inverse thing now. Thanks.