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

Pokémon
Nature
Characteristic
Hidden Power type

Slaking	Base stats	Stats	Possible genes (IVs)
		Level
HP	150	406–436	31
Attack	160	321–352	31
Defense	100	203–233	31
Special Attack	95	193–223	31
Special Defense	65	133–164	31
Speed	100	203–233	31

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

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

And for your copy/pasting pleasure:

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

or start over