Units and Flat Staking
Define a unit as 1-2% of your dedicated bankroll — money fully separate from living expenses. Flat staking (same unit every bet) is the baseline that removes emotion, prevents tilt-chasing, and makes your results measurable in units won rather than dollars.
Kelly and Fractional Kelly
The Kelly Criterion sizes bets by edge: stake fraction = (edge / odds). Full Kelly maximizes growth but produces brutal swings and punishes overestimated edges severely. Most professionals use quarter- or half-Kelly, sacrificing a little growth for far smoother variance.
If you cannot quantify your edge honestly, you cannot use Kelly — default to flat 1% units instead.
Drawdown Reality
Even a genuine 55% bettor hits 10-unit losing streaks. At 1% stakes that's a survivable 10% drawdown; at 5% stakes it's half the roll gone and usually tilt follows. Plan for the losing streak before it happens, because it will.