Now I know I'm not a Professor, but I have noticed a bit of information witch I have been able to base a theory off of. This theory is that the pokemon anime has made a specific type of beginner pokemon as the "hero's beginner", the "rival's beginner", and as I call it the "other beginner". Basicly, I theorized that the Fire Types go to the "hero" the Water Types go to the "rival" and the Grass Type is occasonally seen.
Here are the folloeing trainers and their starter pokemon:
KantoAsh:Charizard
Gary:Blastoies
JohtoJimmy:Typhlosion
Silver:???
*BEGINNER UNKNOWN*(I assume the water to rival Jimmy, and be like the others)
HoennMay:Blazeakin
Brandon:Swapart
ShinohAsh:Chimchar
Jun:Empolion
*WILL GET JUN'S PIC WHEN D/P EPISODE 101 COMES OUT*
Monkey