[PsYkO]

Recently on ladder (masters) i encountered this strategy 3 games straight in a row by the same person.
Essentially the bo for this is pulling 4 drones off at 10 supply after overlord(i believe?) this timing coincides with when your supply depot is about to finish i think and when he reaches your base your rax should be 1/4 completed (based on map distance).
Now having seen this the first time i completely overreacted and thought he was trying to drone block me for a six pool (wasnt thinking straight) so i pulled off every scv except for 1 and tried to push him out of my base for an emergency depot wall off.
After 1 minute of trying and failing i realized he wasnt trying to six pool having seen no zerglings and it didnt help that the 2 scouting scvs i send forth to put proxy 11/11 rax were not in my base mining.
Due to extremely poor micro i lost 2 scvs and heaps of mining time and proceeded to lose the game in a ridiculous fashion with 3k resources lesser than him (He does a eco baneling bust in reaction to my banshee play).
Another thing to note, he steals both my gases after the harass is done (The whole point was him trying to snipe my rax scv). I won the other 2 games afterwards on metalopolis and shakuras because i microed 4 scvs much much better and choked him at the unfinished depot wall (2x2) and mineral walked(is that what they call it?) when my scvs turned red.
Also, his bo involves 17 pool and 18 hatch afterwards i believe.
So what im asking here is what is the best reaction to this type of play, [ I believe it was invented by ROOTCatz in Catz Vs Deth casted by HD quite some time ago (zvt) ]