Odds are prices. They're shaped by probability, margin, market behavior, and risk management—not just "what will happen."
Bookmakers build odds from estimated probability, then include a margin (overround). That's how they get paid regardless of outcome.
Odds shift because of sharp bettors placing informed bets, public money piling into popular teams, and new information entering the market.
Bookmakers don't need perfect predictions. They need balanced exposure.
Even accurate bookmakers can be inefficient in niche leagues, low-liquidity markets, and mispriced assumptions. That's where models can detect edge.