ROI
Return On Investment — tournament profitability
Definition
ROI (Return On Investment) measures a tournament player's profitability: (total winnings − buy-ins paid) ÷ buy-ins paid, expressed as a percentage. A player who invested €10,000 in buy-ins and cashed €12,000 has a 20% ROI: every euro of buy-in returned 20 cents of profit. It's the tournament equivalent of the cash-game win rate in bb/100. Orders of magnitude vary enormously by format and field: in small-stakes online MTTs, very good regs reach 20-30%; as stakes rise and fields toughen, ROIs compress toward 5-15%. In Spin & Gos, where the rake and the 3-player structure leave little margin, an ROI of a few percent is enough to make a big winner on volume. ROI's trap is sample size: tournament variance is such that an ROI measured over a few hundred MTTs means almost nothing — a single big score can swing it from −20% to +40%. It takes thousands of tournaments for observed ROI to converge to true ROI. Until then, decision quality and bankroll management remain the only reliable indicators.
A €25 Spin & Go reg plays 20,000 spins in a year (€500,000 in buy-ins). At 4% ROI they clear €20,000 in profit. The same ROI measured over 500 spins would have no statistical meaning: at that volume, the ROI's standard deviation far exceeds the 4%.