this will work if your emeny is not hacking or has no air units. first u get in the fron of his base on a cliff. then start building photon cannons. he wont know they are there untill u have about 5 in and then he will only be able to hit your cannons 30% of the time. time is very important if u are fast u can completely surround his base. this works very very well on blue night in whatever because the only way up is shuttle which ur cannons will kill before he drops his long range attackers. this will also not let him outs his base with any units because they will stop to attack and be totalled. this work VERY well against protoss ok against terren and not very well against zerg unless u find a way to stop gaurdians. but this will take out all his front defence it will also make it easier to get in with dragoons and zelots.

CreepColony's Opinion: This strategy will waste a lot of time, and won't kill many things. Probably just workers and some units that try to attack your cannos.