In a non-sports context, here how you define an advantage play:

If I could do this play 1 billion times under identical conditions, would I be ahead or behind when it's all over?

If the answer is "Ahead", then it's an advantage play.

Otherwise it's not.

Advantage players don't always win. They sometimes lose due to bad luck, poor bankroll management, or failed application of the play (such as a VP player pr BJ card counter who makes too many mistakes).

But as long as you're playing with a statistical ADVANTAGE, and as long as you make a practice of doing this regularly, you are an AP.