Bankroll Management: The One Skill That Keeps You Alive
Unit sizing, stop-loss rules, and the math behind why most bettors go broke.
What a bankroll actually is
Your bankroll is the money you can lose without it affecting rent, savings, or your relationship. If that number is $0, you don't have a bankroll — you have a hobby that costs money. Be honest about this before you do anything else.
Unit sizing: the only rule
A unit is 1% of your bankroll. You bet between 0.5 and 5 units per play. Most plays are 1 unit. Best Bets are 2-3. A 5-unit bet is one or two times a year.
Why 1%? Because variance in sports betting is brutal. A 55% bettor — better than 99% of people who place bets — will hit losing streaks of 8 or more in a row regularly. If you're betting 5% per play, an 8-game losing streak is a 33% drawdown. If you're betting 1%, it's an 8% drawdown.
Recalculating units
You recalculate when your bankroll changes by 25%, not after every bet. If you start at $1,000 (units = $10) and grow to $1,250, you bump units to $12.50. If you drop to $750, you cut to $7.50.
This is what most people get wrong. They lock in a $100 unit, ride it down to a $4,000 bankroll, and now they're betting 2.5% per play through their worst stretch. Variance kills them. Recalibrate.
Kelly is for people who actually know their edge
The Kelly criterion gives you the optimal bet size given your edge and the price. The problem is most bettors don't actually know their edge — they think they're +5% but they're +0%. Full Kelly with a wrong edge estimate is suicide.
Use fractional Kelly (0.25 to 0.5 of full Kelly) and only on bets where you've genuinely modeled the probability and have a sharp reference price.
Stop-loss rules
Set a daily stop-loss. Most pros use 5% of bankroll. If you're down 5 units in a day, you're done. Walk away. Tilt is real, and the bets you place when you're chasing are -EV almost by definition.
Bottom line
You can have the sharpest picks in the world and still go broke if you bet 10% per play and hit a normal losing streak. Boring bankroll discipline outperforms exciting capping every single time.