Originally Posted by
Poryhedron
You can accumulate Effort any way you wish; defeating 12 Machop, defeating 6 Machoke, defeating 3 Machamp, or defeating a Machamp, 3 Machoke and 3 Machop will all give you exactly the same result as far as building your Effort Values is concerned.
One other thing; the reason you have to wait until L100 to get 1 stat point per 4 EP is because collecting 4 EP grants you (your current level / 100) stat points. So if you're level 25 and have an Attack EV of 64, those 64 EP will raise your Attack by 4 points. At level 50, those same 64 EP will instead raise your Attack by 8 points, and at level 100 they'll be adding their maximum value of 16 points.