WHIRLWIND EXPLANATION: Pokémon have a fixed, permanent score from 0 to 31 for each stat that affects how good that stat can ever get.

This calculator will figure out that score (called a "gene" or, more obtusely, an "IV") for you, so you can discard the unworthy. It's more accurate for higher-level Pokémon, so it's helpful to go into a level 100 wifi battle with someone and check your Pokémon's stats from there.

Stat calculator

Tauros
Tauros 		Base
stats		 Stats Effort Possible genes (IVs)
Level
HP 75
257–288
31
Attack 100
203–233
31
Defense 95
193–223
31
Special Attack 40
84–114
31
Special Defense 70
143–174
31
Speed 110
222–253
31

Congratulations, you've narrowed your Pokémon's stats down exactly!

This Tauros's Hidden Power inflicts Dark damage, with 70 power.

And for your copy/pasting pleasure:

31 HP; 31/31 Physical; 31/31 Special; 31 Speed

or start over