Technical mumbo jumbo. As they said, the EVs stay. All that level does is scale the benefit. IE barring nature, a lv 100 poke gets +63 to a stat with252 EV's. Being toned down to lv 50, that benefit is +32, but you still need all 252 EV's.
If you think 'I only need half the EV's since they are lv 50' you'll only see +16 if you go to 124 or so.
It's why you don't see lv 5's with 75 attack and speed :P
Anyways, meh, who cares abuot my rating, lets try some more :P
Autumn Friendly: 18-4 4 RQ, 1657, 578th place
International challenge: 16-2 7 RQ 1634
Spring friendly: 18-0 1721, 173rd
4527 7711 4773 is my 3ds FC,
Don't have any room for random safari requests :/ Friends list is full as is.