Just use the FF to split the roaches.
StarCraft Master – Round 8 – Safe Zone (With Achievement)
Blink your stalker(s) right between the siege tanks, so they won’t be able to hit you, because of the minimum range. I find it easier to get the achievement by setting one stalker to hold position and blinking to the “safe zone” with the other.
StarCraft Master – Round 7 – Colossus Smash
Walk the colossus up and down the ramp, in a way the zerglings will have to run around to be able to attack it.
StarCraft Master – Round 6 – Burrow Ambush
Burrow the zerglings in the path of the marines and unburrow right when the marines are over them.
StarCraft Master – Round 5 – Retarget
Step back with the targeted stalker so the spine crawler will start attacking the other one. Bring the other stalker back to combat right away.
StarCraft Master – Round 3 – Zealot Choke
Try to get the zealots into a position where many zealots are attacking and the zerglings can’t surround them.