EPTIf there is one thing I learned from scouting is to keep the drone alive. Depending on the map I am in,I am more interested in knowing where my opponent is than what build order he is going for. Once I found that, I can go to a Watchtower where as soon as the Lair finishes up, I can make the Overlord that I placed on the said Watchtower to generate Creep to turn my Drone into either a Spore Crawler or Spine Crawler. It's not a completely effective defense, but it can buy me a bit of time by a nano-second.
