Spotting an Arb
Convert every outcome's best odds to implied probability and sum them. Under 100% means guaranteed profit: +110 on one side (47.6%) and +105 elsewhere on the other (48.8%) totals 96.4% — a 3.6% risk-free margin. Stakes are split so each outcome returns the same amount.
Where Arbs Come From
Slow line movement after news, promotional boosts, and genuine model disagreement between books — especially between sharp books like Pinnacle and slower recreational ones. Typical margins run 1-4%, so meaningful profit needs meaningful stakes and volume.
The Real Risks
Odds move mid-execution leaving you exposed on one side; voided bets on one book break the hedge; and most importantly, recreational books limit or close accounts that show arbing patterns. Round stakes, occasional recreational bets, and spreading volume across many books extend account life — but limits are eventually the cost of doing business.