for those who are really afraid of muta. and is sure that muta is incoming, (scan see lair making, wif more than 2 geyser at around 8m scan~)
you can do anti-timing. 2 fact hellion/ reactor hellion + 4 rax combat shield marine. hit at 9-11 min depending on research timing. damn pain. normally can take out the nat at least.
terran got 2 opening. 1 rax FE or reactor hellion FE
1 rax FE
take 2 gas
make 2 factory, 1 with techlab research blue flame.
make to 4 rax. pump hellion and marines only. research combat shield when gas allows.
reactor hellion FE
make 3 rax after FE
research combat shield
this build is baneling bust proof, going to be nasty if roach rush incoming but the odds of having roach in tvz. lol. anyway you can still transition into marauder with the amount of rax you have.
scan, if see lings, spines, geyser means muta incoming.
try to hit when his spire just pop out, and he had spent the resources to make muta. this is when he cant use the 1k min 1k gas into making ground unit.
transitions into tank marine medivac smoothly with 3rd base.
errr is it really good idea to get 4 barracks...b4 9-11min..