The rule: pick a unit size (typically 1-2% of bankroll) and stick to it. Never "chase" losses by increasing stakes. Never bet more than you can afford to lose. Variance is real, and an undercapitalized bettor goes broke even with a real edge.
Basics
Bankroll management
Sizing bets as a fixed percentage of your total wagering capital — the #1 discipline for long-term survival.
Example
$2,000 bankroll at 1% units = $20 per bet. A 20-bet losing streak (not unusual) leaves you with $1,600 — still in business.