Who's actually outperforming the market? Bet 1 unit on every team, every week, at the closing price. Add it up. The teams above the line have been beating their odds; the teams below have been losing your shirt.
Closing odds are the last published head-to-head prices before kick-off, pulled from aussportsbetting.com's free historical NRL dataset (Pinnacle until April 2018, bet365 until April 2024, BlueBet since). Used under their personal-use Terms.
Cumulative units. For every game a team played, add the closing-odds return: a win pays out (decimal odds − 1) units, a loss loses 1 unit, a draw is a push (0). Sum across the season and you have each team's running total. Favourites need to actually cover their short price to bank units; underdogs need to spring upsets.
Wins above expected. For each game, the closing odds imply a win probability — after stripping the bookmaker's overround so the home/draw/away probabilities sum to 1. Sum those across the season and you get the market's expected-wins number. Subtract actual wins. Positive = the market under-rated the team, negative = the market over-rated them.
The top-8 / bottom-9 split is irrelevant here. A wooden-spoon team can have positive units and a minor-premier can have negative ones — it depends on how the market priced them, not how many points they finished with.