spawn areas (mlg maps)

in a map of mine im working on the spawns and the spawn areas
heres a litte doodle on paint of the spawn areas

u see
1 black box (map)
4 med. blue box (respawn areas)
a flag
some red dots (spawn points)

now im looking for the effect that the mlg foundry maps had (halo 3)
were if there is no enemy in the back spawn area (Dark blue were the spawn areas over lap) that that is were u will most likely spawn
but if an enemy is in the base (or took ur flag) ur more likely to spawn out side the base on either side

any wisdom to share would be greatly appreciated like no back spawn zone, useing weak spawn zones, ect...