Lazy Roulette Calculator: Fast Martingale & Kelly Estimates

Lazy Roulette Calculator — Quick EV & Bet Suggestions

What it is: A lightweight tool that instantly computes expected value (EV) and suggests simple bets for a chosen roulette wheel and stake.

Key features

• Wheel selection: European (single zero) or American (double zero).
• Bet types supported: Single number, splits, streets, corners, red/black, odd/even, dozens, columns, and custom bets.
• Instant EV: Calculates EV per spin for the chosen bet and stake.
• Quick bet suggestions: Ranks a few low-complexity options (e.g., outside bets for lower variance, single numbers for high payout/high variance) based on user’s goal: maximize EV (all bets equal, so shows least-negative loss), minimize variance, or chase high payout.
• Simple bankroll guidance: Shows expected loss per 100 spins and suggests stake as a percentage of bankroll for low-risk play.
• One-click presets: Common bet mixes (e.g., conservative: 2 even-money bets; moderate: single + outside; aggressive: multiple singles).

How EV is calculated

• EV = (probability of win × net payout) + (probability of loss × −stake).
• Uses exact probabilities for chosen wheel: European P(win) and American P(win) differ due to zero(s).

Example outputs (for a \(10 stake on European wheel)</h3> <ul> <li>Single number: EV = (1/37 × \)350) + (⁄₃₇ × −\(10) = approx −\)9.73 per spin.

Red/Black: EV = (⁄₃₇ × \(10) + (19/37 × −\)10) = approx −\(0.54 per spin.</li> <li>Suggested bet (minimize variance): Red/Black, expected loss ≈ \)0.54 per spin.

Limitations & tips

• Does not beat house edge; EV is always negative over long term.
• Suggestions aim to match user goals, not to guarantee wins.
• Use bankroll guidance conservatively; roulette outcomes are independent.