9 Pool (vs. Protoss)
This article refers to 9 Pool without an early gas. For that specific build, see 9 Pool Speed.
This is an aggressive yet safe opening against Protoss. In the commonly seen Fast Expansion, the Protoss usually sends a scout after building the first Pylon, reaching your base in time to stall or keep you from getting your expansion up. 9 Pool prevents this by getting faster Zerglings killing the scouting Probe and allowing you to expand without any problem.
Also, after scouting a 12 Hatch Protoss players tend to get their Nexus up before any Cannons, which makes you and him to be even in bases, which is a clear disadvantage for Zerg (this may even allow the Protoss to get his Gateway up before any Cannons, which will speed up the arrival of his first Corsair). This BO forces the Protoss to build two Cannons before attempting to get his Nexus and in case he goes for the Nexus first or doesn't block his choke with Probes, you can easily do a run-by and do disastrous damage to his Mineral Line.
- 9/9 - Spawning Pool
- 8/9 - Drone
- 9/9 - Extractor Trick (see note) (optional)
- 10/9 - Overlord
- 10th Drone - Scout (optional) (see note)
- @100% Spawning Pool - 6 Zerglings and Natural Hatchery
- 11/17 - two Zerglings (optional) (see note)
Build Order Clarification
9 - Extractor Trick
At 9 control and approximately 70-80 Minerals, send a Drone to build an Extractor, reducing your control to 8. Immediately build a Drone, raising your control to 9. Cancel the Extractor, returning the Drone, and leaving your control at 10/9.
10th Drone - Scout (optional)
On a four-player map, if you haven't scouted your opponent with your Overlord at this point, send this 10th Drone to the closest spawn position. By process of elimination you will be able to tell your Zerglings which base to go to. If your Drone does not scout your opponent at this point, there is little value in sending it to scout the final position, since the Zerglings should be en route by then.
11 - two Zerglings (optional)
If you have not scouted your opponent by this time, make 2 Zerglings to avoid limiting your options against an unknown opponent. If you have scouted him, gauge whether you need the Zerglings on the anticipated amount of early-game aggression.
When your Zerglings arrive, respond depending what you see:
- Against a greedy Protoss who went Nexus first, you should win outright by attacking.
- Against a Protoss who built a single Cannon and brought no Probes to his natural, run in with your initial 6 Zerglings and surround the Cannon. You should be able to disrupt your opponent enough with the remaining Zerglings to essentially secure victory at this point.
- Against a Protoss who built two Cannons, you cannot attack. Simply use the Zerglings to deny Probe scouts while you expand and move into whichever midgame strategy you prefer. If the cannons are out of position, you may attempt a Ling run by to get into the main, which should only have probes. In modern Zerg vs. Protoss, the preferred transition is the 3 Base Spire into 5 Hatch Hydra build, placing your third Hatchery at around 15 supply and the Extractor immediately afterward.
- Against a 2 Gateway rush, you may find yourself in a difficult position. With denying Protoss scouting, you may be able to secure an expansion. More often than not, you should wait for proper scouting and Zergling Speed before attempting to expand. If you didn't scout in time if the Protoss is going for a 2 Gate strategy, make 6 zerglings and save your larva until you do know for sure (or make 2 more zerglings to be safe). Then if he indeed does have 2 Gates, just continue making zerglings until your expansion and a Sunken Colony is done. Try going around the zealots to pick off lonely reinforcements or surround isolated zealots if there's a chance to do so.
In terms of midgame build orders, this build can transition into any plausible mid-game strategy. Such builds include:
- 1 Hatch Lurker
- 2 Hatch Lurker
- 2 Hatch Muta
- 3 Base Spire into 5 Hatch Hydra (vs. Protoss)
- 3 Hatch Hydralisk (vs. Protoss)
- 3 Hatch Zergling (vs. Protoss)
- 3 Hatch Spire (vs. Protoss)
- 4 Hatch before Gas (vs. Protoss)
- 14 Nexus
- Proxy Gateways
- FE with just one Cannon
This build is particularly strong on maps with a wide choke that forces the Protoss to block with more Probes than he would like to. Some examples are: