Hatchery and Sunken placed at 6 natural for better cover.

You would only want to place your 3rd Hatchery in your main side by side with your 1st, if you were playing Blizzard's Lost Temple. When you place your 2nd Hatchery at your natural, a Sunken may be morphed behind both of the Hatcheries. The path to the Sunken has been extended due to the 2nd Hatch taking up a greater amount of space. The Sunken will score more hits before it is reached and destroyed. Where you decide to build your 3rd Hatch at 6, I will leave to your discretion.

Often enough, I see far too many players become intimidated by a scouting Probe, and they resort to building their 2nd Hatchery in their main. Here are some ways to deal with this.
If you find yourself being pestered by a Probe early on as you are expanding, you may have to bring along another Drone to help fight/distract the Probe. Or you can choose to fight the Probe, and when your Drone reaches red health, you can morph and cancel an Extractor at your natural. Your Drones health will be replenished , and you can kill the Probe and build your expansion Hatchery. Since the Probe has delayed your Hatchery building process - keep an eye on your Mineral count. You only need 300 Minerals for the Hatchery, You probably have enough extra minerals to build 2 Drones. Think ahead, and if  you figure the Probe will delay you 100 minerals worth of time, you should build 2 Drones as you are chasing the Probe. By the time the Probe is destroyed you will have 300 Minerals approximately, and that pesky Probe would only have slowed down your Hatch build time, (not your production rate.)

When you spawn at 12 on Lost Temple as Zerg and you send your Drones to the farthest right Mineral patches, it will look like so.

Notice how the Drone moves quite far to the right, and then up towards to the Mineral patch. This is not optimal

Instead set your rally point to the middle Mineral patch. As the Drones hatch, they will procceed to the middle patch and you can split them off to the far right patches like so (Picture on next page.)

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