EVs

Make sure you check the EVs of your Pokemon (or IVs) before you use anything rare on it such as stones, rare candies and evolution items. I recently checked the EVs of my Pokemon and my Teddiursa actually had 5/510 (less than one percent).

 

I also caught a Dratini and Lapras with 0 EV both.

 

When you catch a Pokémon in the wild EVS are always 0/510. I suggest you to look at this website to see how EV are working in Pokémon and how to EV train your Pokémon.
https://pokemondb.net/ev

 

Thank you for informing me, I thought EV worked liked IV.