Last updated: 29 September 2026
Card counting is the one blackjack idea everyone has heard of, and the one most people playing online misunderstand. If you’ve wondered whether learning how to count cards in blackjack is worth the effort, the honest answer depends less on your memory than on how the cards are shuffled.
Key Takeaways
- Card counting tracks how many high cards are left to be dealt. It never tells you which card comes next.
- The Hi-Lo count uses three values, and one division turns the running total into the number that matters.
- Power.Win’s Blackjack Original generates each hand’s cards from a server seed, a client seed and a nonce for that bet, and you can check any hand yourself.
- Whether a count means anything depends entirely on how, and how often, the cards are shuffled.
- Nevada law treats a counting device very differently from counting in your head.
The Hi-Lo card values below are the whole count. Every card you see gets one of three numbers.
| Card rank | Hi-Lo value | Cards of that value per 52-card deck | Why it gets that value |
|---|---|---|---|
| 2, 3, 4, 5, 6 | +1 | 20 | Low cards; once they’re gone, the rest of the shoe is richer in tens and aces |
| 7, 8, 9 | 0 | 12 | Neutral; their removal barely changes your odds, so the count ignores them |
| 10, J, Q, K, A | −1 | 20 | High cards; each one dealt leaves fewer blackjacks and fewer dealer busts in the shoe |
Twenty cards count +1 and twenty count −1, so a full deck always adds up to zero. That’s why the Hi-Lo is called a balanced count.
What is card counting?
Card counting is a way of keeping a running score of the cards already dealt, so you know whether the cards still in the shoe favor you or the dealer. It’s a mental tally, not a memory feat: you don’t remember individual cards, you add and subtract as they appear.
So what does it mean to count cards? It means estimating the mix of what’s left, and more tens and aces than usual help you for three reasons. Blackjacks pay 3:2 on many tables and come more often. The dealer, who must draw to 16, busts more often. And your doubles land on ten-value cards more often.
A shoe full of small cards does the reverse. The dealer makes more hands, and your blackjacks thin out. On a six-deck shoe, you’re dealt a natural about 4.75% of the time on average; counting only tells you when that chance has drifted up or down.
The idea came from mathematician Edward O. Thorp, whose 1962 book Beat the Dealer showed that blackjack’s odds shift as cards leave the shoe. Every count used today, including the Hi-Lo, builds on that finding.
How do you count cards with the Hi-Lo count?
You count cards with the Hi-Lo count by adding 1 for every 2 to 6 you see, subtracting 1 for every ten-value card or ace, and ignoring 7, 8 and 9. You start at zero after a fresh shuffle and keep one number in your head.
Here is one round, card by card, from a fresh shoe:
- 4 → +1 (running count +1)
- K → −1 (0)
- 6 → +1 (+1)
- 2 → +1 (+2)
- 9 → 0 (+2)
- 5 → +1 (+3)
- A → −1 (+2)
- 3 → +1 (+3)
After eight cards the running count is +3. More low cards than high cards have left the shoe, so what remains is slightly richer in tens and aces.
If you’re learning how to count cards in blackjack for the first time, the Hi-Lo is the usual starting point, because it has only three values and no side counts. The Wizard of Odds Hi-Lo reference lists the same values and uses the same conversion to a true count.
How does card counting work at the table?
Card counting works at the table by converting the running count into a true count: running count ÷ decks still to be dealt. The true count is what tells you how rich the remaining shoe is, because +4 means far more in one deck than in six.
In the running→true count table, each row is a point in a shoe, and the true count is the running count divided by the decks remaining.
| Shoe size (decks) | Cards dealt | Decks remaining | Running count | True count |
|---|---|---|---|---|
| 8 | 83 (20%) | 6.4 | +4 | +0.6 |
| 8 | 208 (50%) | 4.0 | +4 | +1.0 |
| 8 | 312 (75%) | 2.0 | +4 | +2.0 |
| 6 | 208 | 2.0 | +6 | +3.0 |
| 6 | 156 | 3.0 | −3 | −1.0 |
Worked example. An eight-deck shoe holds 416 cards. After 20% of it, about 83 cards, 333 remain, which is 333 ÷ 52 = 6.4 decks. A running count of +4 becomes 4 ÷ 6.4 = +0.6. Treat that +4 as if it were the true count and you might raise a $10 bet to $50. You’d be putting five times the money on a shoe that has barely moved from neutral.
What does a positive count mean for your bets?
A positive true count means the remaining cards favor you slightly, and counters raise their bets at those points. That bet spread, not the count itself, is what produces any edge, and it’s also what makes a counter visible to the casino.
The size of that edge is small. In Wizard of Odds simulations on a six-deck shoe, a Hi-Lo counter’s advantage ranged from 0.157% (a 1-to-5 bet spread, four decks dealt) to 1.182% (a 1-to-15 spread, five decks dealt, full set of strategy changes). Every cent of it depends on counting perfectly, estimating decks correctly and playing basic strategy without a slip.
The results still swing hard. With basic strategy on six decks where the dealer stands on soft 17, a hand wins 42.43% of the time, pushes 8.48% and loses 49.09%, according to the Wizard of Odds variance tables.
Over 100 hands at $10 ($1,000 wagered), that’s roughly 42 wins, 8 pushes and 49 losses. Five losses in a row happen in about 2.85% of five-hand runs, roughly 1 in 35.
For anyone who isn’t counting perfectly, the house edge stays in place on every hand. A small, conditional edge with large swings is not a reliable source of money.
How do you practice counting cards?
You practice counting cards with a deck countdown: turn over a shuffled 52-card deck one card at a time, keep the running count, and check that you finish at zero. Because the deck is balanced, any other final number means you slipped.
Build it up in stages:
- Deck countdown. Count a single deck aloud until you reach zero every time. Then count silently.
- Last-card check. Hold back one card face down. If your count after 51 cards is +1, the hidden card must be a ten or ace; if it’s −1, a 2 to 6; if it’s 0, a 7, 8 or 9.
- Cancel pairs. Turn two cards at a time. A king and a 5 cancel to zero, so you learn to see pairs as one value.
- Add the division. Stack a few decks in a discard pile and practice judging how many decks remain, in half-deck steps. Then convert running counts to true counts.
- Add basic strategy last. Counting on top of a strategy you haven’t memorized only adds errors. Learn the blackjack basic strategy chart first.
Do all of this with a real deck at home, where nothing is riding on it.
Is card counting illegal?
Card counting in your head is not listed as a crime in Nevada’s gaming law; using a device to track cards is. NRS 465.075 makes it unlawful to use, or possess with intent to use, a device that keeps track of cards played at a licensed gaming establishment.
Under NRS 465.088, a first offense is a category C felony. The statute’s list covers devices, software and hardware; the mental count you do with your own memory isn’t on it. You can read the full text of NRS 465.075, which reproduces the Nevada Legislature’s wording.
Legal isn’t the same as welcome. A casino is a private business and can refuse your play if it thinks you’re counting.
Counting in your head is one question; whether you can play blackjack online at all is another, and the answer changes with your country and state. Check your local law and Power.Win’s terms of service, which set out the countries the site is closed to, before you play.
Can you count cards in online blackjack?
No, not in standard RNG blackjack, because these games typically reshuffle the virtual deck before every hand. The count resets to zero with every deal, so there’s never a shoe for it to build in.
Live dealer blackjack is different in principle, because a real shoe is dealt. In practice, three things work against a count:
- Deck count. Live tables commonly deal from six- or eight-deck shoes, which dilute each card’s effect. How deck count moves the base house edge is covered in how many decks are used in blackjack.
- Penetration. A cut card is placed before the end of the shoe, so the last part is never dealt. The Wizard of Odds treats 4.5 decks dealt out of six as normal penetration, and the biggest true counts tend to come late in the shoe, in the part a shallow cut card never reaches.
- Continuous shuffling. Some tables return cards to the shoe after each round, which works like a fresh shuffle every hand.
Why does a count fail on continuous-shuffle and live tables?
A count fails there because it needs time to build, and these tables don’t give it that time. On a continuous shuffler the count is always zero. On an eight-deck shoe, the first fifth barely moves the true count at all.
Back to the worked example: after 83 cards of an eight-deck shoe, a running count of +4 is a true count of only +0.6. With the cut card ending the deal partway through, you can play most of a shoe near zero, at the ordinary house edge.
Can you count cards at Power.Win’s blackjack tables?
No count carries over at Power.Win’s Blackjack Original, because each bet’s result is generated from the server seed, your client seed and a nonce that rises by 1 per wager. The cards for a hand are produced for that bet, and there’s no shoe carrying over for a count to track.
The Original’s rules panel states no deck count. It does state the rules you’d check at any table: blackjack pays 3:2, insurance pays 2:1, and the dealer stands on all 17s, including soft 17 (what that rule changes is covered in what a soft 17 is).
What you can do instead of counting is check the deal. The server seed’s hash is shown before you bet, and when you rotate seeds the original server seed is revealed so you can confirm the hash matches.
The Power.Win provably fair page explains the inputs, and verifying a result yourself walks through a check step by step. You can see the rules panel on the Blackjack Original itself.
Live blackjack with crypto sits in a separate Blackjack Lobby, alongside RNG blackjack variants. Those tables come from third-party studios and are certified by their providers, which is a different claim from provably fair: you can’t reproduce a live hand from seeds.
Read the rules card on each live table for its decks and shuffle method before you assume anything about a count.
Both the Original and the lobby run under one licence. Power.Win is licensed by the Tobique Gaming Commission, licence 0000209, operated by 3-102-968317 SRL (Costa Rica), and you can read what that covers in who licenses Power.Win.
Checked on power.win/games/blackjack and the lobby on 29 September 2026.
Frequently Asked Questions
Does card counting actually work?
Only under narrow live conditions: a dealt shoe, deep penetration, a wide bet spread and error-free play. Even then you lose about 49.09% of hands, and the count does nothing on RNG or continuous-shuffle tables.
How big is a card counter’s edge over the casino?
At best it flips a small house edge into a small player edge of 0.157% to 1.182%, in six-deck simulations with 1-to-5 up to 1-to-15 bet spreads. Miscount, misjudge the decks or leave the cut card shallow, and the house edge returns.
Where did card counting come from?
It came from mathematician Edward O. Thorp. His 1962 book Beat the Dealer showed that blackjack odds change as cards are removed from the shoe, and later counts such as the Hi-Lo built on that finding.
Is counting easier with one deck?
Yes, the arithmetic is kinder. Each card is a bigger share of what’s left, so a running count of +4 with one deck remaining is a true count of +4, against +0.6 with 6.4 decks left.
What is the easiest way to count cards?
The Hi-Lo count, with three values: +1 for 2 to 6, 0 for 7 to 9 and −1 for tens and aces. Its full-deck total is zero, which gives you a built-in accuracy check when you practice.
Should you hit a hard 15 against a dealer 10?
Yes, unless the table offers surrender, in which case basic strategy surrenders it. Without surrender, you hit a hard 15 against a dealer 10 in a four- to eight-deck game, as the hard totals chart shows. Learn that chart until it’s automatic before you add a count.
Sources
- Edward O. Thorp, Beat the Dealer, 1962. The origin of card counting.
- Nevada Revised Statutes 465.075 and 465.088, Nevada Legislature (NRS chapter 465, read 29 September 2026). Device offenses and penalty.
- Wizard of Odds, High-Low card counting. Hi-Lo values, true count and simulated player advantage.
- Wizard of Odds, Variance in Blackjack. Per-hand win, push and loss rates.
- Power.Win blog, Blackjack Basic Strategy Explained. The chart every count sits on top of.
Take the Lead, Gamble Responsibly
Counting cards doesn’t make blackjack a way to make up losses, and no count, pattern or bet size removes the house edge for a player who isn’t counting perfectly. Decide what a session is worth before you start, take breaks, and never double up to win back what you’ve lost.
Power.Win gives you deposit limits (daily, weekly or monthly), self-exclusion from three months up to five years or indefinitely, and reality checks. You’ll find them, along with support resources such as BeGambleAware, on the responsible gambling page.
By the Power.Win Editorial Team.