having polygons tat r penetratable only from one way - its usefullness:
ie. have a relatively big spawn place that u can only get out one way and once u do u can't pass through it again backwards

second reaosn "could" be tat like ie. inf. warehouse where u can esc. with the flag from the tunel and all the way at the end u can only go out and not back into the tunel
(im not suggesting tat tats wat we should do to this map but im using it as an example to show "how" it can b used)

Has been suggested, use the Search Function.

HAHA!!!!!! my idea. go search for it. it's the best idea never to be implemented!!!
it's better to make 1 post with a bunch of ideas, than a bunch of posts with 1 idea.