Bankroll rules are your safety net. They turn a short-term swingy game into a long-term, survivable edge.
Even perfect play loses in the short run. Blackjacks are clustered, double-downs swing hard, and long losing streaks are normal. A bankroll plan keeps you in action long enough for your edge to show.
The math is simple: if your unit size is too large for your bankroll, normal variance will knock you out before EV can recover. If your unit is too small, you survive but never earn meaningful hourly EV. The goal is balance.
A betting unit is the minimum bet at the table. Most counters size units as a percentage of bankroll. Use this table as a starting range:
| Bankroll | Conservative Unit (0.25%) | Standard Unit (0.5%) |
|---|---|---|
| $2,000 | $5 | $10 |
| $5,000 | $12 | $25 |
| $10,000 | $25 | $50 |
| $25,000 | $60 | $125 |
If table minimums are higher than your unit, you are effectively overbetting. Move down in stakes or increase bankroll before scaling up.
The Kelly criterion calculates the optimal fraction of bankroll to bet for maximum long-term growth. In blackjack, the edge is small and variance is large, so full Kelly is extremely volatile.
Most disciplined players use fractional Kelly:
If you want a simple rule: bet 0.5% of bankroll as your unit and scale your spread by true count. That approach behaves like fractional Kelly in most shoe games.
Risk of ruin (RoR) estimates the chance you will lose your bankroll before your edge has time to recover. It depends on unit size, spread, penetration, and how well you count.
Run your plan through the risk of ruin calculator. If RoR is above 10%, your plan is aggressive. If it is under 5%, you are in a safe zone.
Session rules are behavioral tools. They do not increase EV, but they prevent bad decisions.
This example assumes a $10,000 bankroll, 6-deck S17, and a 1-8 spread:
| True Count | Bet (Units) | Bet ($) |
|---|---|---|
| TC ≤ 0 | 1 | $50 |
| TC +1 | 2 | $100 |
| TC +2 | 4 | $200 |
| TC +3 | 6 | $300 |
| TC +4+ | 8 | $400 |
Adjust the spread downward if penetration is shallow or if you are still perfecting your count accuracy.
A common target is 300 to 500 units. That size gives you enough runway to survive normal variance without ruin.
Start with 0.25% to 0.5% of bankroll as your base unit. That is conservative and lets you learn without extreme swings.
No. Fractional Kelly is more realistic and still keeps you near optimal growth.
Use a stop-loss to protect discipline and reduce tilt, not because it improves EV.