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 Stats Effort Possible genes (IVs)
Level Level
HP 75
172–192
27–28
Attack 100
135–155
31
Defense 95
128–148
30–31
Special Attack 40
57–77
2–3
Special Defense 70
96–116
24
Speed 110
148–168
14–15

Hmm, I need more information to figure out your Pokémon's genes exactly. Try raising it to level 66 and entering its new stats.
Remember: if your Pokémon battles at all, you'll need to track the effort it gains. Consider saving your game and using Rare Candy instead.

And for your copy/pasting pleasure:

27–28 HP; 31/30–31 Physical; 2–3/24 Special; 14–15 Speed

or start over