You did not fail because your edge vanished.
60-70% of failed prop challenges end on a drawdown violation — a sizing decision, not a signal. Every one of those decisions is measurable before you place a trade. These pages show how, with worked numbers rather than principles — the arithmetic of drawdown limits, losing streaks and what your stop can actually reach.
Why prop firm challenges fail: it is almost never the strategy
60-70% of failed challenges end on a drawdown violation, not on a losing strategy. Four sizing decisions do nearly all of the damage, and every one of them is visible before you place a trade — we show them with worked numbers: a stop that sits past the liquidation price, and fixed-dollar sizing that keeps betting from an account that can no longer fund the trade.
Max drawdown vs daily drawdown: the two rules that end most challenges
Trailing, static, equity-based or balance-based — prop firms measure drawdown in ways that change what you are allowed to risk per trade by a factor of three. Here is how each variant is calculated, which one bites first, and the position size each one actually permits.
My backtest passed but I failed the challenge: nine reasons why
A backtest that shows a smooth curve and a challenge that ends in a drawdown violation are usually the same strategy measured two different ways. Nine specific gaps between the two — survivorship, look-ahead, costs, the horizon exit — each with what it does to the result when you remove it.
Position sizing for a prop challenge: the only maths that matters
Profit targets are reached by surviving, not by sizing up. The arithmetic of risk per trade against a drawdown limit, why fixed-lot sizing fails a challenge specifically, and the four numbers to read off your own history before paying a fee.
Run your strategy through the same engine
Describe it in plain English. The AI compiles it; the anti-bias engine tests it on up to 3 years of real data and shows the warnings before the profit. Free to start.
Test a strategy free → See famous strategies fail