First game was a 6pool on shattered which i was lucky to scout quickly. I hadn't even put down my gateway yet. So I calmly put the gateway in the normal spot, finally fought off a blocking drone to lay the forge to wall-in, but neglected to *immediately* plug the "hole" at the corner between the buildings. When the lings showed up a second later, they ran through the hole and took out the main pylon. gg.
Second game was a 7pool on Shakura's. This time I guessed wrong on the scout and came to his base basically just in time to see the lings spawn. I quickly put the forge in place and this time immediately plugged the hole, queueing a zealot and 2 cannons as soon as buildings are ready. EVEN THEN, the initial lings destroyed both the forge and gateway with me unable to do anything. Z figured he'd done enough damage and backed off, rather than try and run past the cannons (I couldn't build new buildings fast enough to keep the wall). I had an eco advantage but not a huge one, and had to start my tech over from the beginning. 200 minerals worth of lings destroyed 300 minerals worth of buildings. I 4gated him before he could recover too much and won but *barely*. It wasn't an auto-win at all. And I'm sure he could have done a runby if he'd timed it when I left my base but hadn't plugged the hole. Or could have run in and killed workers if he wished. It was satisfying to finally beat it, but frustrating how specific the defense has to be to prevent a loss, when the attack is so mind-numbingly brain-dead simple.
I feel like even though I set the buildings perfectly I only squeaked out a win and took so much damage. Please tell me if this is how holding off the ling rush is supposed to go, because I don't get the "auto-lose" part to this at all. I am also aware that there are other strats for defending besides the forge wall-in, but this one seems to have community consensus of being the most reliable. If you disagree, I'm open to ideas.