Beginner's Guide to Card Counting
Everything you need to go from curious to counting.
The Basics
What is Card Counting?
Card counting is a legal strategy used by skilled blackjack players to gain a mathematical edge over the casino. It works by tracking the ratio of high cards (10s and Aces) to low cards (2–6) remaining in the shoe. When the remaining deck is rich in high cards, the player has a statistical advantage and should bet more. When it's rich in low cards, the casino has the edge and you should bet the minimum.
Contrary to popular belief, card counting doesn't require a photographic memory. It's a simple running tally anyone can learn with practice. Casinos don't like it, but it's completely legal.
Most people look at card counting as this magical ability to almost know what cards will be coming. The truth is way more complicated than that. The advantage in card counting comes when you zoom out to thousands of hands. If you are a fan of blackjack and have played a fair amount, you know that sometimes you go in and can't lose a hand, while other times you go in and can't win a hand. You may have seen a table one night where everyone walked away thousands of dollars richer with nobody counting one single card. Yet we all know that "the house always wins." That's because over thousands of hands, day in and day out, the law of large numbers brings the winnings back to them. That's the way the game was designed. This is the same for advantaged play. You don't learn how to count cards, go into the casino, and simply win every hand now that you have this learned ability. You have to play for a certain amount of hands for the odds to actually pan out in your favor. A lot of hands.
Step One
Perfect Blackjack
Before you count a single card, you need to master basic strategy. This is the mathematically optimal play for every possible hand against every possible dealer upcard. Basic strategy reduces the house edge to around 0.5% — the lowest of any casino game.
Most players lose more money to strategy mistakes than to bad luck. A wrong decision — hitting when you should stand, or failing to double when the math demands it — costs you real money over time. redjack drills every scenario until the right play becomes automatic.
You cannot count cards effectively without first playing perfectly. Master this first.
Again, it isn't about what feels right or what should or shouldn't happen each hand. Many people learn perfect strategy, yet their bodies and minds won't let them actually play it because "but this time I know a 10 is coming and the dealer might have a 4 under there." You might be completely correct. But if you play like that every time, you will lose even more than if you don't. The math is done. Once again, it's a matter of thousands of hands. Not one (or even a bunch). If you play with these rules, you will cut the dealer's edge down to half of a percent.
Step Two
Hi-Lo Counting
The Hi-Lo system assigns a value to every card as it's dealt:
You keep a running total in your head called the Running Count as cards are dealt. A positive count means more high cards remain in the shoe, which favors you. A negative count favors the dealer.
The True Count adjusts the running count for how many decks are left, giving you a more accurate picture of your edge. Divide the running count by the number of decks remaining to get the true count.
There are 52 cards in a deck. 20 of them have values 2 to 6, and 20 of them have a value of 10 or 11/1, while 12 of them have a value of 7, 8, or 9. If we know that more low cards have been played than high cards, we know that there are more high cards coming. If we know that more high cards have been played than low cards, we know that more low cards are likely to come soon. That's all we're trying to determine with our Hi-Lo counting.
Step Three
Bet Spreads
Knowing the count is only valuable if you act on it. When the count is in your favor, you bet more. When it's not, you bet the minimum and wait.
| True Count | Bet Size |
|---|---|
| TC ≤ +1 | 1 unit (minimum) |
| TC +2 | 2 units |
| TC +3 | 4 units |
| TC +4 | 8 units |
| TC +5 or higher | 12 units (maximum) |
Your betting unit is derived from your bankroll — typically 1/300th to 1/500th of your total blackjack bankroll. This keeps your risk of ruin low while maximizing your edge over time.
We know that the value of card most frequent in the deck is 10 — there are 16 of them, while there are only 4 of every other value. This is why we make most of the moves we make in perfect play. Doubling on an 11 is valuable because 10 is the most likely card you'll draw, and a 10 on your 11 gives you 21. Staying with a 14 is valuable when the dealer is showing a 6 because the most likely card in the deck is a 10 — if there's a 10 under the dealer's 6, their total is 16, and the most likely card coming off the deck will bust them. Of course this isn't the case every time, but 10 shows up more than any other single value. If we can keep track of how many 10s have been used compared to lower cards, we can find a moment where the advantage swings from the dealer to us. And that's when we strike. We bet more when we're more likely to win and less when we're less likely to win. Then we let the law of large numbers take us over the finish line.
Step Four
Combined Practice
Once you can play perfect strategy automatically and maintain an accurate count under pressure, it's time to put it all together. In a real casino you're doing all three things simultaneously: playing perfectly, tracking the count, and sizing your bets — all while carrying on a conversation and not looking like you're counting.
redjack builds this skill in three progressive tiers:
Complete all three tiers and you're ready to walk into a casino and practice for real. That is: you're ready to play redjack.
Keep in mind that a casino is a whole other world with all sorts of added stress and distractions. When you feel you're ready, take the transition slowly. Go play some hands. Try to keep count from afar or while playing casually. And make sure you understand that wild swings can still happen while you're playing, counting, and playing perfectly. It's a long game. Don't forget that!