EPTNow while Morrow doesn't do this build as well as TLO does, he has spent time learning it from TLO, and is better than 99.99% of the people you will run into on the ladder, so for the vast majority of you it should be useful to take a look at what White-Ra does to counter this build.
Game 1: White-Ra v Morrow
Game 2: White-Ra v Morrow
Game 3: White-Ra v Morrow
Game 4: White-Ra v Morrow
Morrow gives up on the 3-1-2 at this point, but for those of you who want to see how the BO5 ends...
Game 5: White-Ra v Morrow
White-ra tries stargate tech, 1-base blink stalkers, and fast expanding against the 3-1-2 build.
While it is probably possible to make any of White-ra's counters work, my personal take on the 3-1-2 build after watching these replays is that the strongest response is a fast-expand. I have a fairly complicated analysis of why that is, here it goes:
Gateway units are extremely cost effective against just mass marines (obviously). However, each banshee that gets added to that marine mass makes the Terran army slightly more cost effective than it was before against Protoss tier 1 and tier 2 units.
There reaches a point ~around~ 6 banshees where the Terran army becomes cost effective against the Protoss army, and soon becomes strong enough to roll over a 1-basing Protoss. Unfortunately, this timing works out badly for the Protoss since it comes before he can get T3 units out with a gateway army.
So colossi-stalker, or templars, are out of the picture.
Day9 always says: If you can't hard-counter, you can win by just having more units.
There is this fairly lengthy period before the Terran gets a high banshee count in which the Protoss player can defend the Terran push fairly easily with production from just 3 warp gates. The way I see it, your main goal against the 3-1-2 is to get your expansion up, pay it off, and mass extra units BEFORE the Terran gets that critical cost-effective amount of banshees out.
So if you scout with your observer that 3-1-2 has gone down, you are guaranteed (as a result of the huge infrastructure costs and building time) that they will be unable to hit you with a devastating push for a considerable amount of time. At that point I think the best thing to do is throw down the 2nd nexus. Throwing down the nexus early not only lets you get a army size advantage to combat the Terran, you may force the Terran to attack you before he wants to, and ultimately it helps you tech to, and support, templar or colossi production as you go into the mid game.
While I have a theory behind the fast-expansion, I'm not convinced that a better way doesn't exist; this is just the best that I have come up with so far. Any discussion, variation, criticism, etc. is welcome.
Also, any other theories, discussion, or side-notes about the 3-1-2 is welcome.
