From looking at the FAQ and playing this game for years I know that the more you battle the pokemon the closer to that 64000 whatever stat experience you can get to max out your stats but what I haven't really seen is what pokemon give which stat boost or is it just a general +1 to all 6 stats until they max out?
Such as in Gen 3 onwards you get stats from certain pokemon such as Haunter giving you a special stat to your EV but in gen 1 I haven't found anything as to which gives what and how much only that it doesn't matter what level the opponent is. --- Just because I don't invite you into my bedroom doesn't mean you're not more than welcome into my living room
I don't know the complete mechanics of it, but to put it simply: the pokemon gives you stat exp equal it it's stats, i.e.:
battle nothing but diglett/dugtrio and your attack and speed increase more than your other stats
battle nothing but Geodude/Gravelar and your defense will increase more than your other stats.
Just to clarify, pokemon give stat exp. equal to their base stats, so level won't matter. Base stats for every pokemon can be found in a FAQ here. --- She went after her kids with super love, they turned into drugs. - LastManStanding