By CardCount Academy · Reviewed · 6 min read
Every balanced counting system uses two numbers. The running count is what you keep in your head as cards are dealt. The true count is what you actually use to size your bet and make decisions. Mixing them up is one of the most common beginner mistakes.
The running count
With a balanced system such as Hi-Lo, the running count starts at 0 after a shuffle. Each dealt card adds its tag: +1 for 2–6, 0 for 7–9 and −1 for tens and aces. For example, if the first eight cards are 4, K, 6, 2, 9, A, 5 and 10, the running count moves like this:
+1, 0, +1, +2, +2, +1, +2, +1 — so the running count is +1.
You only ever carry one number. Don't try to remember the cards themselves, and don't recount from the beginning. Spotting pairs that cancel out (a 5 and a king together add up to 0) is the fastest way to keep up.
Why the running count isn't enough
A running count of +6 means six more low cards than high cards have left the shoe. If six decks are still to be dealt, those extra high cards are spread across about 312 cards and barely change anything. If only one deck is left, the same six extra high cards make up a noticeable share of the 52 remaining. Same running count, very different situation.
The true count fixes this by expressing the surplus per deck remaining.
How to convert
True count = running count ÷ decks remaining.
- Estimate the decks already dealt by looking at the discard tray.
- Subtract from the total in the shoe. A six-deck shoe with about 2.5 decks in the discard tray has about 3.5 decks left.
- Divide the running count by that number.
| Running count | Decks left | Working | True count |
|---|---|---|---|
| +9 | 3 | 9 ÷ 3 = 3 | +3 |
| +9 | 4.5 | 9 ÷ 4.5 = 2 | +2 |
| +10 | 4 | 10 ÷ 4 = 2.5 → round down | +2 |
| +6 | 1 | 6 ÷ 1 = 6 | +6 |
| −5 | 2 | −5 ÷ 2 = −2.5 → round down | −3 |
Rounding: pick one rule and stick to it
Players round true counts in different ways. Some round toward zero (so −2.5 becomes −2), some round down (floor, so −2.5 becomes −3), and some estimate decks to the nearest half or whole deck. The differences are small. What matters is using the same rule every time so your bets and decisions stay consistent. The tools on this site estimate decks to the nearest half deck and round the result down.
Estimating decks remaining
You don't need to be precise. Learn what one deck, half a deck and a quarter of a deck look like in a discard tray, and estimate to the nearest half deck. Errors of a quarter deck rarely change your decision. Practicing with real cards — stacking 26, 52 and 104 cards — helps build the reference.
Unbalanced systems skip this step
Systems like KO and Red 7 are unbalanced: their tags don't add up to zero over a full deck. They start from a negative number that depends on the number of decks, so that the running count itself behaves like a true count at the moments that matter. Instead of converting, you watch for a key count and a pivot. That makes them easier to use, at the cost of some precision.
Common mistakes
- Betting from the running count in a balanced system.
- Dividing by the total decks in the shoe instead of the decks remaining.
- Forgetting to reset to zero after the shuffle.
- Losing the count while estimating decks — keep the running count, then glance at the tray.
Ready for a full system? Read the Hi-Lo guide.
Educational content only. Card counting does not guarantee winnings, casinos can limit or refuse play, and laws differ by location. Read the disclaimer and, if gambling stops being fun, our responsible gambling page.
Sources and further reading
- Wizard of Odds — Card Counting: Introduction
- Wizard of Odds — Introduction to the High-Low Card Counting Strategy
- Stanford Wong, Professional Blackjack (Pi Yee Press).