What is the best race

Stim speed my friend, Stim Speed. have fun trying to catch a stimed rine against fast zealots. They point isnt to have no loss. It's to create bigger loss. Im also sure that you heard of those wonderful medic

A stimed rine can do 4 attack every 3 second for those that have hard time to picture it a good shoot every 3 sec. So a marine deal (without weapon upgrade) 24 dmg every 4 sec. More you have marine faster the damage raise and harder it is to get in melee range.