Betting calculators

PlusEV Lab is a free set of betting-strategy calculators and simulators built on one idea: math instead of luck. Whether you bet on sports, spin roulette, or grind poker, these tools show you the real numbers behind every system — the edge, the variance, and the honest probability of going broke.

Everything runs in your browser. No sign-up, no ads chasing you, no data leaving your device. Pick a tool below and see what the math actually says.

What does +EV (positive expected value) mean?

Expected value (EV) is the average result of a bet if you could repeat it forever. A +EV bet makes money on average; a −EV bet loses on average. The name PlusEV Lab is a reminder that the only durable way to win is to find genuine positive expected value — not to chase a clever-looking progression.

Casino games are deliberately −EV: roulette pays you as if there were 36 numbers while the wheel has 37 or 38. No staking system changes that. In sports betting, +EV exists when your estimated probability beats the bookmaker's implied odds — and that is exactly what the Kelly calculator is built to size.

Do betting systems actually work?

Progressive systems like Martingale, D'Alembert, Fibonacci, and Labouchère feel like they work because they win small amounts most of the time. But they only rearrange when you win and lose — they never change the expected value. On a −EV game, every one of them loses over time.

The fastest way to prove this to yourself is the risk-of-ruin simulator: run any system thousands of times and watch the 'went broke' percentage climb. Math beats faith.

The tools

Risk of Ruin Simulator — run 10,000 sessions of Flat, Martingale or D'Alembert and see your true probability of going broke. Kelly Criterion Calculator — size bets optimally when you have an edge. Martingale Calculator — see how fast doubling eats a bankroll. Labouchère Tracker — run the cancellation system without losing your place. Bankroll Tracker — log every bet and see your real ROI and win rate.

FAQ

Is there a winning roulette strategy?expand_more

No staking system beats roulette, because every bet is −EV by design. Systems change the shape of your wins and losses but never the long-run expected value. The simulator demonstrates this directly.

What is the safest betting system?expand_more

Flat betting (the same stake every time) has the lowest risk of ruin of any common system. It still can't beat a −EV game, but it bleeds slowest and survives longest.

Martingale vs D'Alembert vs Fibonacci — which is best?expand_more

They differ in how aggressively stakes grow after a loss (Martingale fastest, D'Alembert slowest), but all share negative expected value on house-edge games. Compare their ruin rates head-to-head in the simulator.

Can you beat the house edge with math?expand_more

Not on pure chance games like roulette or slots. You can win only where genuine +EV exists — advantage play (e.g. card counting), or sports betting where your probability estimate beats the odds. Then Kelly tells you how much to bet.

Are these tools free?expand_more

Yes, completely free, no account and no installation. Everything runs in your browser and your data stays on your device.