◒ EDGETHE COIN LAB PLAY MONEY ONLY
A SMALL GAME ABOUT BIG DECISIONS

You have an edge.
Can you keep it?

A biased coin. $25 to start. 100 flips to find your balance.

THE EXPERIMENTFLIP 000 / 100
60% chance of heads · 1:1 payout
FORTUNE FAVOURS DISCIPLINEHHEADS · EDGE LAB
STAY IN THE GAMETTAILS · EDGE LAB
The next flip is yours.
YOUR BANKROLL
$25.00
A fresh start. Make it count.
%
0% · sit it out100% · all in
CALL YOUR SIDE
SPACE flip · ENTER autoplay
THE LONG GAME

Watch your edge compound.

You $25.00Kelly $25.00Same coin tosses
Every flip writes the next part.
WIN RATE—
PEAK BANKROLL$25.00
MAX DRAWDOWN0.0%
RECENT FLIPSH heads · T tails
No streaks. No stories. Yet.
✳
KNOW YOUR EDGE

Being right is only half of it.

Bet too little and you leave growth behind. Bet too much and a losing streak can end your run.

60%
Kelly stake on heads20% of bankroll

Odds stay fixed during a run. Start a new run to change them.

THE KELLY CRITERION

A good bet can still ruin you.

If heads wins 60% of the time and a win earns your stake, you have an advantage. But betting your whole bankroll means a single loss ends the game.

For an even-money bet, Kelly’s fraction is 2p − 1. At 60% odds, that is 20% of your current bankroll on heads. It maximizes expected logarithmic growth under these assumptions; it does not guarantee a winning run.

Try half Kelly, full Kelly, and all in. The purple line uses full Kelly on exactly the same tosses as you. Changing your stake changes future flips only.

Each run lasts 100 flips, or ends when you have less than one cent. Amounts are calculated without rounding and displayed to two decimal places. This is a play-money probability experiment.