You only get paid for disagreeing

If you buy a contract at the price everyone else agrees on, and the price is fair, your expected return is roughly zero minus costs. Edge is not a feeling of confidence. It is a measurable, repeatable gap between your probability and the market's, on the side where you turn out to be right.

Two things have to be true at once

You have to disagree. A forecaster who tracks the market perfectly is well-calibrated and has no edge. They are reporting the consensus back to itself. And you have to be calibrated when you disagree. Confidently wrong is worse than agreeing, because it is expensive rather than merely pointless.

Agreeing with the market is free. Disagreeing is what costs, and what pays.

How to find out whether you have one

1. Record the probability, not the trade. Write down what you thought before you saw the price. Without that, every review is contaminated by the market's answer.
2. Score it against outcomes, with sample size attached. Twenty resolved markets is a story; two hundred is evidence.
3. Split by domain. Almost everyone who has an edge has it somewhere specific and gives it back everywhere else. The average conceals both.
4. Compare to the base rate. Being right 80% of the time on things that happen 80% of the time is not skill.

Which is why we build the scoreboard and not the call. Your probability, your record, split by domain, so an edge you think you have is one you can prove.