RE: The Competitive Battling Simple Questions Thread
Individual Values, aka IVs, are a hidden number determining the stats of your Pokemon. Each Pokemon has 6 IVs, one for each stat, and each IV can take a number from 0 to 31. The highest the number, the closest the stat will be to its maximum number. For example, a Pokemon with 100 Base Speed at Level 100 will have 31 points of Speed less if it has 0 instead of 31 IVs in Speed. The IVs of a Pokemon are numbers associated with it and can't be changed, So if you want to reset a Pokemon's IVs, you'll have to catch/breed it again.
Effort Values, aka EVs, determine the stat growth. A Pokemon can have a total of 510 EVs spread across its stats, with the highest number of EVs possible in a stat being 252. At Level 100, every 4 EVs are increasing the stat they're invested in by 1 point, meaning that a Pokemon with 252 EVs in a stat will have 64 more points in that stat than a same Pokemon with 0 EVs. EVs are earned through battle, medicine (e.g. Protein) and Super Training. In Super Training, it's easy to keep track of which and how many EVs a Pokemon gets. Things are a bit different in battle. Whenever you KO a Pokemon, your own Pokemon that scored the KO will gain from 1 to 3 EVs. The amount and kind of EVs depend on the Pokemon-if you KO a Gardevoir, for example, you'll receive 3 Special Attack EVs. Every Pokemon awards a specific set of EVs when defeated. Also, unlike IVs, EVs can be reset. Using the stat-reducing Berries (e.g. Tamato) or a Reset Bag, the Pokemon's EVs decrease, so you are able to train it again and give it the EVs you wish.