Now this is luck and not skill, but I traded Pokémon in Pokémon GO with a friend. When you do this, the Pokémon you send to your friend rerolls its IVs. The Duskull I sent him rerolled its IVs, the Buneary he sent me rerolled its IVs, and we both ended up with perfect-IV Pokémon.
(I’m a 100-IV aka perfect-IV hunter in Pokémon GO. In the mainline games, I tend not to care as much.)