A real edge can still blow up a bankroll if you bet too big. The Kelly criterion gives the mathematically optimal stake for long-run growth — and most pros bet a fraction of it to smooth the ride.
KalEdge finds the +EV spots; this sizes them. Free to start.
Full Kelly = (p × decimal − 1) / (decimal − 1), where p is your win probability. It maximizes long-run growth — but it's volatile, and it's brutal if your probability is even slightly off.
Because your edge is always an estimate, most disciplined bettors stake a fraction — quarter or half Kelly — which keeps almost all the growth with far less risk of ruin. When there's no edge, Kelly says stake nothing. That discipline (bet only when +EV, size it small) is exactly how KalEdge frames every pick.