This idiom or expression-like phrase means:

Steady.
In a balanced way.
A condition of equal opportunity.
No particular advantage in any direction.

This idiom or expression refers to:

An advantage (over others) at the beginning of a task.

We’re so confident in our team that we’ll give you a five minute head start. Go ahead. We’ll wait five minute before we start.

Asset:
A positive point, an advantage, a good thing to have.

Welcome to our company. Having you on our team is a great asset!

Liability:
A negative point, a disadvantage, a bad thing to have.

When someone says: He’ll be a liability for us, they mean: His presence will hurt us more than it will help; If we keep him, it won’t be good for our image; etc.

This idiom or expression like phrase means:

Advantage.

When someone says: We have the upper hand in the negotiation, they mean something like:

We have an advantage over them.
We’re in a better position than them.

Q. Do you want to negotiate with Richard?
A. Not really. I have the upper hand here.

This idiom or expression has to do with:

Having an advantage.

You should be more careful because she has an important edge over you.