Bankroll & Bet Spreads
The money management system behind successful advantage play
Why Bankroll Management Matters
Even with a mathematical edge, short-term variance can wipe you out. Card counting gives you roughly a 1-2% advantage, but individual sessions swing wildly. Without proper bankroll management, your edge means nothing.
Think of it this way: you are the casino. Casinos have huge bankrolls relative to individual bets because they know variance is real. They can weather any losing streak because their bankroll can absorb it. You need the same cushion.
Key stat: Without proper bankroll sizing, 40%+ of card counters go broke despite having a mathematical edge. The edge only works if you survive long enough for it to play out.
Sizing Your Bankroll
The simplest rule: divide your total bankroll by 500 to get your betting unit. This gives you enough cushion to survive the inevitable downswings.
| Total Bankroll | / 500 | Betting Unit |
|---|---|---|
| $5,000 | = | $10 |
| $10,000 | = | $20 |
| $25,000 | = | $50 |
This gives approximately 1% risk of ruin when using a 1-8 bet spread.
Bet Spread Examples
Your bet spread is the ratio between your minimum and maximum bet. A wider spread extracts more profit from favorable counts but also draws more attention from casino surveillance.
6-Deck Shoe
Standard spread. True count changes more gradually in shoe games, so a narrower spread is sufficient.
2-Deck Game
Wider spread needed. True count swings are larger in double-deck, creating bigger opportunities (and bigger swings).
Trade-off: A wider spread means more profit per hour, but also more “heat” from the casino. Most counters use 1-8 in shoe games as a balance between profit and longevity.
True Count → Bet Mapping
This table shows how to scale your bets based on the true count. At negative or neutral counts, bet the minimum. As the count rises, ramp up aggressively.
| True Count | Bet (Units) | Example ($10 unit) |
|---|---|---|
| ≤ 0 | 1 unit | $10 |
| +1 | 2 units | $20 |
| +2 | 4 units | $40 |
| +3 | 6 units | $60 |
| +4 | 8 units | $80 |
| +5+ | 10-12 units | $100-$120 |
TC +1 is still colored red because your edge at +1 is minimal. The real money is made at TC +2 and above.
Kelly Criterion Simplified
The Kelly Criterion is a formula for optimal bet sizing. It tells you exactly how much of your bankroll to wager based on your edge and the variance of the game.
Full Kelly
Bet = (Edge / Variance) × Bankroll
Maximizes long-term growth rate, but the ride is extremely volatile. Drawdowns of 50%+ are common.
Half Kelly (Recommended)
Bet = (Edge / Variance) × Bankroll × 0.5
Halves the bet size. You give up ~25% of growth rate but dramatically reduce risk of ruin and drawdown severity.
Warning: Full Kelly is too aggressive for most players. Even small errors in estimating your edge (which are inevitable) can lead to overbetting and ruin. Half Kelly provides a much-needed safety margin.
Risk of Ruin Table
Risk of ruin is the probability of losing your entire bankroll before doubling it. More units = lower risk.
| Bankroll (Units) | Risk of Ruin |
|---|---|
| 200 units | ~40% |
| 400 units | ~20% |
| 500 units | ~10% |
| 750 units | ~5% |
| 1000 units | ~1% |
Pro tip: Most serious counters aim for 1000+ units (1% risk of ruin). This means a $10 minimum bettor needs at least $10,000 dedicated to their bankroll.
Session vs Total Bankroll
Total Bankroll
Your entire card counting fund. This is the full amount you have dedicated to advantage play. Never risk money you cannot afford to lose.
Session Bankroll
What you bring to one casino visit. Typically 30-50 betting units. This limits your exposure in any single session.
Iron rule: If you lose your session bankroll, leave. Do not go to the ATM. Do not chase losses. The math works in your favor over thousands of hands, not in a single session.
When to Move Up or Down
Moving Up
Move to the next stake level when your bankroll sustains 500+ units at that level. For example, move from $10 units to $25 units when your bankroll reaches $12,500+.
Moving Down
Move down immediately if your bankroll drops below 300 units at your current level. Do not wait and hope for a recovery at the higher stakes.
Discipline check: Never move up just because you had a big winning session. Wait for sustained bankroll growth over many sessions. One big win does not change the math.