Zerg wall is a tool to slow down SpeedZealot pushes, Vultures, and Zergling run-by. It is somehow a must in modern ZvP and against 1/1/1 in ZvT.
- Hydra leaky, but Zealot tight
Hatchery-Hydra Den Relationship
Hatchery-Evolution Chamber Relationship
Evolution Chamber-Hydra Den Relationship
Hydra Den-Creep Colony Relationship
Evolution Chamber-Creep Colony Relationship
Spire-Creep Colony Relationship
Hatchery-Creep Colony Relationship
Spire-Evolution Chamber Relationship
This hatchery and sunken forms a Vulture tight wall, Zerglings keep the only way for Vulture to get by closed, it will be targeted by the sunken and shut down. Hatchery is being exposed, but by the time Vultures pew-pew the hatchery to half life, Mutalisks or Hydras should be out. When facing bio play, emergency Evolution Chambers are useful to hinder their movement before sunkens fully mutate, or second tier Zerg units get out. You can stop building them when you're safe.
Bottom left location on Circuit Breakers: Vulture Wall
Bottom right location on Fighting Spirit: Emergency Evolution Chambers
When an opponent has more Zerglings, it is possible to create a corridor that makes only few lings fighting. Zerglings cannot surround, thus losing effectiveness of their numbers.
Bottom right location on Colloseum: Drone drill saves a well guarded sunken
Top right location on Fighting Spirit: 2 Zergling gap in the natural
They key is to block Zealots while keeping Hydras and Zerglings able to flow between the buildings. Adding a second "emergency" Evolution Chamber is a viable strategy to make a tighter wall during the engagement. Be aware that ranged Dragoons can snipe your walling buildings.
Top location on Medusa: Zealot tight with leaks for Hydras and Zerglings.
Why would you throw the game with Ultralisks anyway?