there is no best hero.
its all about skills n quick thinking.
imagine fv vs enchantress for example,
if early game enchantress owning with her high damage ulti,
fv sure cant farm at all.
n at last sure lose cause cant farm at all.
however, enchan can farm very well n many good items.
btw, 1 on 1 is not recommended.
DOta is all about teamwork.
5 on 5 you can plan your strategy with ur teammate.