In "Pokémon" video games, the normal odds of encountering a shiny Pokémon in the wild are 1/8,192, or about 0.01 percent. However, in the third-generation Ruby and Sapphire games, a trainer ID glitch can be exploited at the very beginning of the game, resulting in a 100 percent wild shiny Pokémon rate.
In order to properly perform the glitch, the player must press the A button exactly at the correct frame during the brief introduction. Just as the professor says "Well, I'll be expecting you later. Come see me in my Pokémon Lab," the player can press A as they view the character shrinking. Depending on the frame at which the player pushed A, his Trainer ID will be different. Once in the game, view the ID on the Trainer Card, and use any online service or application to convert the ID number to a hexadecimal. This data value can be found online and mathematically calculated to determine the delay and frame number at which shiny Pokémon can be encountered. Furthermore, if the frame is too difficult, it can be made easier and also affect Pokémon innate values, or IVs. This can be further exploited to catch a wild, shiny Pokémon with perfect IVs.