Blackjack is a race to 21 against the dealer, and it is the rare casino game where your choices change the math. Play every hand by the chart and a good 6-deck game gives the house only about half a percent. Guess, play “by feel” or copy the dealer and that edge grows several times over. Card counting goes a step further: it tells you when the remaining cards favor you, so you can bet more then. This guide covers the rules, the basic strategy for the default game in Casino Coach (6 decks, dealer stands on soft 17, double after split, no surrender, European no-hole-card), what each rule is worth, and how counting works.
How to play
- Bet. Place your wager inside the table minimum and maximum.
- The deal. Every player gets two face-up cards. The dealer takes one upcard. In a US game the dealer also takes a face-down hole card. In a European no-hole-card (ENHC) game the dealer’s second card comes after everyone has acted.
- Check for blackjack. An ace plus any ten-value card is a blackjack. With an ace showing, the dealer offers insurance. In a peek game the dealer checks the hole card for blackjack before you act. In ENHC nobody knows until the end.
- Act on your hand. Hit (take a card), stand, double (double your bet and take exactly one card) or split a pair into two hands. Some games also offer surrender, giving up half your bet.
- The dealer plays by fixed rules. Hit 16 or less, stand on 17 or more. “S17” means the dealer also stands on soft 17 (A♠ 6♦). “H17” means the dealer hits it.
- Settle. Beat the dealer’s total without busting and you win even money. Blackjack pays 3:2 at good tables. Ties push. If you bust, you lose at once, even if the dealer busts later. That one rule is where the house edge comes from.
Payouts
| Bet or result | Pays | Notes |
|---|---|---|
| Win | 1:1 | Includes doubled and split hands |
| Blackjack (3:2 table) | 3:2 | The standard you want |
| Blackjack (6:5 table) | 6:5 | Costs about 1.39% vs 3:2 |
| Blackjack (1:1) | 1:1 | Costs about 2.27% vs 3:2 |
| Insurance | 2:1 | Loses about 6.8% of the insurance bet (6 decks) |
| Surrender | Lose half | Only where the rules allow it |
| Push | Bet returned | Includes blackjack vs blackjack |
A 21 made after splitting is not a blackjack. It pays 1:1 and loses to a dealer blackjack.
Strategy
Basic strategy is the mathematically best play for every hand against every dealer upcard, for one set of rules. It is not a guess or a style. It comes from computing the expected value of each option. The Casino Coach default chart is for 6 decks, S17, double after split (DAS), no surrender, ENHC with “lose all”. The trainer has the full chart and grades every decision against it. Here are the rules that cover most hands.
Hard totals
| Your hand | Play |
|---|---|
| 8 or less | Always hit |
| 9 | Double vs 3–6, otherwise hit |
| 10 | Double vs 2–9, hit vs 10 or ace |
| 11 | Double vs 2–9, hit vs 10 or ace (ENHC) |
| 12 | Stand vs 4–6, otherwise hit |
| 13–16 | Stand vs 2–6, hit vs 7 or higher |
| 17 or more | Always stand |
The memory hook for 12 to 16: the dealer’s 2 through 6 are “bust cards,” so let the dealer take the risk. Against 7 through ace, assume a ten in the hole and keep drawing. So K♣ 6♥ against a dealer 10 is a hit. It feels wrong, but standing loses more often.
Soft totals (hands with an ace counted as 11)
| Your hand | Play |
|---|---|
| A,2 and A,3 | Double vs 5–6, otherwise hit |
| A,4 and A,5 | Double vs 4–6, otherwise hit |
| A,6 | Double vs 3–6, otherwise hit |
| A,7 (soft 18) | Double vs 3–6 (stand if you can’t), stand vs 2, 7, 8, hit vs 9, 10, ace |
| A,8 and A,9 | Always stand |
Soft hands can’t bust with one more card, so they are your best doubling chances against weak upcards. Standing on A♦ 7♠ against a 9 is one of the most common leaks.
Pairs
| Pair | Play |
|---|---|
| A,A | Split, except hit vs ace (ENHC) |
| 10,10 | Never split, stand |
| 9,9 | Split vs 2–6, 8, 9. Stand vs 7, 10, ace |
| 8,8 | Split vs 2–9, hit vs 10 or ace (ENHC) |
| 7,7 | Split vs 2–7 |
| 6,6 | Split vs 2–6 |
| 5,5 | Never split. Play it as hard 10 |
| 4,4 | Split vs 5–6 only |
| 2,2 and 3,3 | Split vs 2–7 |
Insurance and even money: never, with basic strategy.
Why ENHC changes 11 vs 10 and 8,8 vs 10
In a US peek game, the dealer checks for blackjack before you act. If you’re still playing, you know the dealer doesn’t have one. You double 11 against a 10 and split 8s against everything.
In the European no-hole-card game under the standard “lose all” rule, a dealer blackjack shows up after you act. It takes everything you put out, doubles and splits included. With a 10 showing, the dealer makes blackjack about 7.8% of the time. With an ace showing it is about 31%. That turns three plays around:
- 11 vs 10: doubling puts two units at risk against that 7.8% chance. Per the research behind the trainer, using Wizard of Odds 6-deck values, hitting is worth about +0.031 bets and doubling about +0.008. So you hit. Against an ace the risk is far higher, so you hit there too.
- 8,8 vs 10 or ace: splitting is about −0.594 bets and hitting about −0.571. Both are bad hands, but hitting loses a little less. Against a 9 there is no blackjack risk, so you still split.
- A,A vs ace: splitting doubles your exposure to a 31% blackjack chance, so you hit.
If a casino uses “original bets only” (you lose just your first bet to a dealer blackjack), these plays revert to the US chart. Casino Coach’s Strategy tab shows charts for both peek and no-peek games.
Common mistakes
Costs below are per occurrence, in units of your bet, from Wizard of Odds 6-deck S17 peek-game values:
- Standing on 8,8 vs 7. Costs about 0.80 bets. Splitting turns a terrible 16 into two hands that start with 8.
- Splitting 5,5. Against a 6 it costs about 0.54 bets compared with doubling your 10.
- Not doubling 11 vs a 6. Hitting instead costs about 0.34 bets. Doubling is where most of your winning money comes from.
- Splitting 10s. Against a 6 it costs about 0.26 bets. A 20 is already a winner.
- “Never bust” play: standing on 12–16 vs 7 or higher. Standing on 16 vs 7 costs about 0.07 bets, and it comes up all the time.
- Taking insurance or even money. Insurance loses about 6.8% of the side bet. Even money with a 3:2 blackjack costs about 0.04 bets. (At a 6:5 table, a straight even-money offer is the better choice, but the real fix is to avoid 6:5 tables.)
House edge explained
The house wins because you act first: if you bust, you lose even when the dealer busts too. Basic strategy cuts that edge to under 1%. After that, the rules decide the rest. These effects are from Wizard of Odds’ rule-variation tables:
| Rule | Effect on house edge |
|---|---|
| Blackjack pays 6:5 instead of 3:2 | +1.39% |
| Dealer hits soft 17 (H17) | +0.22% |
| No double after split | +0.14% |
| No-hole-card, lose all (ENHC) | +0.11% |
| Double on 9–11 only | +0.09% |
| Late surrender | −0.07% (S17) |
| Single deck instead of 8 | −0.48% |
Some common games, with basic strategy:
| Game | House edge |
|---|---|
| 6 decks, S17, DAS, peek | ≈0.40% |
| 6 decks, S17, DAS, ENHC (Casino Coach default) | ≈0.52% |
| 6 decks, H17, DAS, late surrender (typical Strip shoe) | ≈0.53% |
| 2 decks, H17, DAS | ≈0.45% |
| 6 decks, H17, DAS, late surrender, 6:5 | ≈1.92% |
Casino Coach’s own engine plays 200,000 rounds of the default rules with basic strategy and measures 0.54%, in line with the published figure. The main lesson: the payout on blackjack matters more than any other rule. Check the felt for “Blackjack pays 3 to 2” before you sit down.
Card counting
Basic strategy assumes a full, fresh shoe. But cards come out of the shoe and stay out until the shuffle. When many small cards are gone, the rest of the shoe is rich in tens and aces. That favors you: blackjacks become more likely, and the dealer busts more often. Counting tracks this with simple arithmetic, entirely in your head.
Running count and true count
Each card gets a tag. In Hi-Lo, 2 through 6 are +1, 7 through 9 are 0, and tens and aces are −1. Add the tags as cards appear: that is the running count. A +6 running count means very different things with one deck left versus five, so you divide by the decks remaining to get the true count. Running count +6 with 3 decks left is true count +2. Players estimate decks remaining from the discard tray, to the nearest half deck, and round the true count down.
As a rule of thumb, each +1 of Hi-Lo true count adds about 0.5% to your edge. In a 6-deck game you break even at about true count +1.
The 8 systems Casino Coach trains
| System | Level | Type | Notes |
|---|---|---|---|
| Hi-Lo | 1 | Balanced | The standard. Most published index plays use it |
| KO | 1 | Unbalanced | Counts 7s as +1. No true-count step (6 decks: start at −20) |
| Red 7 | 1 | Unbalanced | Red 7s +1, black 7s 0. No true-count step (6 decks: start at −12) |
| Hi-Opt I | 1 | Balanced | Aces are 0. Keep a side count of aces for betting |
| Wong Halves | 3 | Balanced | Fractional tags (+½, +1½). Very accurate for betting |
| Hi-Opt II | 2 | Balanced | Strong for playing decisions. Ace side count |
| Zen | 2 | Balanced | Aces are −1, so no side count needed |
| Omega II | 2 | Balanced | Aces are 0. 9s are −1 |
Higher-level systems use +2 and −2 tags. They are more accurate but harder to keep at speed. Unbalanced counts like KO and Red 7 add up to a positive number over a full deck. You start from a negative number and bet off the running count. That makes them easier at a busy table.
Bet ramps and index plays
Counting pays through bet sizing. You bet the minimum when the count is neutral or negative and raise as it climbs. Casino Coach’s default ramp is a 1-to-12 spread on the floored Hi-Lo-equivalent true count:
| True count | +1 or less | +2 | +3 | +4 and up |
|---|---|---|---|---|
| Bet (units) | 1 | 4 | 8 | 12 |
Index plays are changes to basic strategy at certain counts. The best known are Hi-Lo’s “Illustrious 18.” Take insurance at true count +3 or higher. Stand on 16 vs 10 at 0 or higher. Stand on 15 vs 10 at +4. Published index tables exist for Hi-Lo. For Hi-Opt I and II, Casino Coach scales the Hi-Lo indices and marks them “approx.”
Bankroll and variance
Even a well-played count gives you only a small edge, often well under 1%, and the swings are large. In one model of a 6-deck game with 75% penetration and a 1-to-12 spread, the expected win was about 0.0121 units per round with a standard deviation of 3.91 units. At a $25 table that works out to about $30 an hour. A 5% risk of losing the whole bankroll takes about $47,000, and you need roughly 1,000 hours of play before the edge reliably shows through the noise. Casino Coach’s bankroll calculator computes risk of ruin, hourly win rate and Kelly bet sizes for your own rules and spread.
The legal side
Counting cards in your head is legal in the US. It is not cheating. But casinos are private property. They can ask you to stop playing blackjack, flat-bet you, shuffle early, or in Nevada bar you. Using any device to track cards at a real table is a crime. In Nevada it is a felony under NRS 465.075. Casino Coach is a training app for practice at home. Every card comes from its own simulated shoe. Never use it, or any other app, in a casino.
Practice in Casino Coach
Casino Coach plays a full table of one to seven players with a real 2-, 4-, 6- or 8-deck shoe and free chips that have no cash value. Trainer mode grades every decision against the chart for your rules. On a mistake it shows the right play and the expected value of every option. You can also block wrong moves until you correct them. Casino mode deals at a realistic pace with no interruptions but still logs every decision. A hidden count panel shows the running count, true count, ace side count and recommended bet when you peek. The trainer also asks you for the count during play. The Drills tab includes Tag Recognition, adaptive Strategy Flashcards, Deck Countdown (casino-ready is 25 seconds or less), Flash Count, Table Round Count, Deck Estimation, True Count Conversion, Bet Ramp and Index Plays. Analytics shows a chart-shaped error heatmap, actual results vs expected value, count-check accuracy, bet-vs-count discipline and an edge waterfall. Train free and find out exactly where your game leaks.
Blackjack FAQ
What is the house edge in blackjack with basic strategy?
About 0.4% to 0.6% in a good 6-deck game that pays 3:2. A 6-deck game with S17, DAS and a peek is about 0.40%. The European no-hole-card version Casino Coach uses by default is about 0.52%. A 6:5 blackjack payout adds roughly 1.4% on top.
Why should I hit 11 against a dealer 10 in some games?
In a no-hole-card (ENHC) game the dealer has not checked for blackjack, and a dealer blackjack takes your whole doubled bet. With a 10 showing that happens about 7.8% of the time, which makes hitting slightly better than doubling. In a US game where the dealer peeks first, you double.
Should I ever take insurance?
Not with basic strategy. In a 6-deck game insurance loses about 6.8% of what you put on it. Card counters take it only at high counts, around a Hi-Lo true count of +3.
Is card counting illegal?
Counting in your head is legal in the US, but casinos are private property and can ask you to stop playing, shuffle early or bar you. Using any device to track cards at a real table is a felony in Nevada under NRS 465.075.
How big a bankroll does a card counter need?
Much more than most people expect. In one model of a 6-deck game with a 1-to-12 spread at a $25 table, a 5% risk of ruin needs about $47,000 and the expected win is about $30 an hour.
Which card counting system should a beginner learn?
Hi-Lo is the usual first choice: level 1, balanced, and the system most published index plays are built for. KO and Red 7 skip the true-count step, so they are easier at the table but less precise.
Practise Blackjack until it's automatic
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Updated October 24, 2026