>>53201653In Gen I and II, the defeated Pokémon's base stats are given as EVs. That's why people call it stat experience for those games, because you're no longer gaining 1-3 points per battle where a stat caps at 255 (252 Gen VI+).
If you defeat a Pidgey, you get
>HP: 40>Attack: 45>Defense: 40>Speed: 56>Special: 35And stat experience caps at 65535 per stat. The way the math works, it's the same as having 63 additional points by level 100 like EVs, the math is just more unwieldy. The other difference is that there's no collective 510 cap (or equivalent 131,070), you can raise every stat by its maximum 63 points.
Where things get a bit more complex is IVs (or DVs which is how people differentiate them from IVs). IVs are 0-31 and serve as that many extra points at level 100. DVs are 0-15, and that value multiplied by 2 is the extra points, so it's actually +2, +4, +6... ...+30 max. DVs are generated for Attack, Defense, Special, and Speed (this is the order by the way), and the HP DV is the first bit of each. So if your DVs for those four stats are all 8 (1000) or higher, your HP is a guaranteed 15 (1111).
0000 = 0, 1000 = 8
0001 = 1, 1001 = 9
0010 = 2, 1010 = 10
0011 = 3, 1011 = 11
0100 = 4, 1100 = 12
0101 = 5, 1101 = 13
0110 = 6, 1110 = 14
0111 = 7, 1111 = 15
Now the problem is that the RNG in the game isn't perfect and doesn't generate every combination (65,536) of DVs. It does for Pokémon of certain encounter types and area encounter frequencies, but perfect DVs aren't possible for a number of Pokémon because of the areas they're found in. Mind you with breeding in Gen II, this should mostly be fixable.
