In ZVZ, Mutalisks are a good stepping stone for you to:
1) Get your third faster than opponent
2) Get total and utter map control
3) Force either infestors, or infestor fungals, or spore crawlers, a LOT
4) You can hunt down at least 4-5 overlords in EVERY GAME. Really.
Now, my failure with them is that sometimes I forget that they are transitionary only, and fall behind on ground units, then he comes in with 30-40 roaches. THAT is bad. I should prepare for that with my own roaches/fungals, and stop making mutas after 6-8.
1) Get your third faster than opponent
2) Get total and utter map control
3) Force either infestors, or infestor fungals, or spore crawlers, a LOT
4) You can hunt down at least 4-5 overlords in EVERY GAME. Really.
Now, my failure with them is that sometimes I forget that they are transitionary only, and fall behind on ground units, then he comes in with 30-40 roaches. THAT is bad. I should prepare for that with my own roaches/fungals, and stop making mutas after 6-8.