Learn · basics and beyond

Short lessons.

A few minutes each, one visual each. New? Start with the basics. Played before? Jump to next steps, or open Going deeper under any lesson. Using Blindspot explains the coach and your stats, and the counting track is there when you want more. Tap any underlined word for a quick definition.

01 / 16 · The basics

How a round plays out

You , get two cards, and play your hand against the dealer's. Get closer to 21 than the dealer without going over. Step through one round.

Going deeper

The other players don't play against you, and what they do doesn't change your odds on average. Seat order only decides who acts first: to .

Next: Hand values ↓
1 / 6 · Bets go out
Dealer
—
You
$10

Everyone puts a bet in their circle before any cards come out. You play against the dealer, not the other players.

02 / 16 · The basics

Hand values

Number cards count their number, J, Q and K count 10, and an ace counts 1 or 11, whichever helps. A hand where the ace counts 11 is ; otherwise it's . Over 21 is a .

Going deeper

An ace and a ten-value card as your first two cards is a : it beats any other 21 and pays 3 to 2. 21 made after a split doesn't count as blackjack.

Next: The dealer's rules ↓
Build a handSoft 17

An ace is counting as 11, so this is soft: one more card can't bust it (the ace would drop to 1).

03 / 16 · The basics

The dealer's rules

The dealer has no choices: they hit until 17 or more, then stand. So their tells you a lot. A 2 to 6 is weak and busts often; a 7 to ace usually makes a strong hand.

Going deeper

Whether the dealer stands or hits on soft 17 ( or ) changes a few moves and adds about 0.2% to the house edge. Against a 10 or an ace, the numbers here assume the dealer has already checked for blackjack.

Next: Hit or stand ↓
Dealer shows 6Busts 42%
1717%
1811%
1911%
2010%
2110%
Bust42%
Where the dealer ends up (after checking for blackjack)

A 6 is a weak card: the dealer busts about 42% of the time. That's why you stand on more hands against it.

04 / 16 · The basics

Hit or stand

Hands of 12 to 16 () are the hardest. The rule of thumb: stand when the dealer shows 2 to 6, hit when they show 7 or more. Pick a hand and see what each move is worth.

Going deeper

The one exception is 12: hit against a 2 or a 3, since only tens bust you and the dealer busts too rarely with those cards. Against a 10, 16 loses whatever you do; hitting just loses a little less (and surrendering, where allowed, less again).

Next: Doubling and splitting ↓
16 against 10Best: Surrender
Surrender−$50
Hit−$53.98
Stand−$54.04
Double−$107.97
Average result per $100 bet

Surrender. You get half your bet back. Played out, 16 against a 10 loses about 54 chips for every 100 bet, more than the 50 you give up.

05 / 16 · The basics

Doubling and splitting

and put more chips out when the odds favour you. Always split aces and 8s, never split 10s, and double 11 against everything but an ace.

Going deeper

These moves are where a good player wins back most of the house edge. Doubling 11 against a 6 wins about $67 per $100 on average; just hitting wins about $33. Splitting 8s against a 10 still loses, but loses much less than playing 16.

Next: Soft hands ↓
11 against 6Best: Double
Double+$66.74
Hit+$33.37
Stand−$15.37
Surrender−$50
Average result per $100 bet

Double. From 11, a ten-value card (the most common card, 4 in every 13) gives you 21. The dealer's a 6 is weak, busting 42% of the time. Double your bet while you're ahead.

06 / 16 · Next steps

Soft hands

With a , one card can't bust you, so you can be bolder: soft 17 or less always hits (or doubles), soft 19 and 20 stand, and soft 18 depends on the dealer.

Going deeper

Soft 18 is the most-missed hand in blackjack: stand against 2, 7 and 8, double against 3 to 6, and hit against 9, 10 and ace. It looks like a good total, but against a strong dealer card it wins less than hitting.

Next: Surrender and insurance ↓
A,7 against 9Best: Hit
Hit−$10.07
Stand−$18.32
Double−$29.02
Surrender−$50
Average result per $100 bet

Hit. Soft 18 looks good, but the dealer's a 9 often makes 19 or 20. One card can't bust you.

07 / 16 · Next steps

Surrender and insurance

saves chips in a few bad spots: give up half your bet instead of playing on. is the opposite: a side bet that loses over time, so never take it.

Going deeper

Late surrender (after the dealer checks for blackjack) is worth about 0.09% to the player with good rules. Insurance only makes sense for a card counter when the true count is +3 or more.

Next: Luck and swings ↓
Insurance: $5 on a $10 betPays 2 to 1
Dealer has blackjack4 in 1331%: you win $10
Dealer doesn't9 in 1369%: you lose $5
On average−$0.38about 8% of the $5

Surrender is the opposite: a move that saves chips in a few bad spots. 16 against a 10 loses about $54 per $100 if you play it out; surrender loses exactly $50.

08 / 16 · Next steps

Luck and swings

One round is mostly luck; thousands of rounds are mostly maths. You can play every hand right and still lose a session, so judge your moves, not your results.

Going deeper

A round of blackjack has a standard deviation of about 1.15 bets. Over 1,000 rounds that's about ±36 bets, while the house edge costs only about 5: luck is far bigger than skill over an evening. It takes tens of thousands of rounds for the edge to show clearly.

Next: The house edge and table rules ↓
10 players · 1,000 rounds each · perfect strategy · $10 bets

Everyone here plays every hand perfectly, with the same small house edge. 4 of 10 still finished ahead. After 1,000 rounds, luck is still much bigger than the edge: judge your moves, not your results.

09 / 16 · Next steps

The house edge and table rules

The is the share of each bet the casino keeps on average. With good rules and perfect play it's under half a percent. Change the rules and watch it move.

Going deeper

The biggest rule is the blackjack payout: instead of 3 to 2 adds about 1.4%, more than all the other rules together. Fewer decks help the player a little; the solver here treats the shoe as endless, which is closest to 6 or 8 decks.

Next: The table screen ↓
House edge with perfect play0.43%
Per $100 bet$0.43the casino keeps, on average
Per hour at $10$3.47about 80 rounds an hour
10 / 16 · Using Blindspot

The table screen

Everything on the table at a glance: the dealer's cards, every seat's hand and bet, the , and the count if you turn it on. Tap a part to see what it shows, then find it in a coached game.

Going deeper

Totals marked S are soft. The shoe bar shrinks as cards are dealt; when the comes out, the dealer finishes the round and shuffles a new shoe.

Next: The coach ↓
The tableDealer
Count +3 · True +1
DealerShowing 10
18$10Stand
Iris$415
S17$10
You$390
13$10
Hank$380

The dealer's cards along the top: the up-card, and the hole card face down until everyone has played.

11 / 16 · Using Blindspot

The coach

After each move the coach says if it was the best one, why, and what a different move would cost on average in chips (its ). When two moves are nearly equal, it calls it a close call and accepts either.

Going deeper

The coach's maths assumes an endless shoe, which matches the published charts for 6 and 8 decks. In two spots where real shoes flip the answer by less than a chip per $100 (soft 13 against a 5, soft 15 against a 4), it follows the chart.

Next: Your blindspots ↓
You stand on hard 16 against 5$10 bet
Stand: right

The dealer shows a 5 and busts 42% of the time. Hitting 16 risks busting first, so stand and let the dealer take the risk.

Stand−$16.72
Hit−$44.95
Surrender−$50
Double−$89.90
Average result per $100 bet
12 / 16 · Using Blindspot

Your blindspots

Your mistakes aren't random: most people miss the same few hands again and again. The site groups them by kind of hand, shows which costs you most, and drills it.

Going deeper

A kind of hand counts as a blindspot once it has come up at least 6 times and you missed it at least a quarter of the time. The costliest shows first, because a missed double costs more than a close call on soft 13.

Next: Why counting works ↓
The blindspot loop

After each round, Your hands marks any move that differs from the chart and says what it cost.

13 / 16 · Advanced: card counting

Why counting works

Cards that have been dealt don't come back until the shuffle. When lots of low cards have gone, the shoe is rich in tens and aces, and that favours you: more blackjacks, better doubles, and more dealer busts. Counting tracks that.

Going deeper

Counting is legal, but casinos don't like it: they may limit your bets or ask you to leave. Online games that shuffle every round can't be counted. This track is for understanding the game, and for fun.

Next: The running count ↓
True count 0Player edge -0.4%
TC -4-2.4%
TC -2-1.4%
TC 0-0.4%
TC +20.6%
TC +41.6%
TC +62.6%
Rough edge for the player at each true count (about +0.5% per point)

Here the house still has the edge. Counters bet the minimum and wait.

14 / 16 · Advanced: card counting

The running count

The system tags every card: 2 to 6 is +1, 7 to 9 is 0, and tens and aces are −1. Add them up as they come out; that total is the . Try a deck.

Going deeper

Practise in pairs: a low and a high card cancel, so you can skip them. A full deck always counts back to zero, which makes a good self-check. Aim for a deck in under 30 seconds before playing with the count on.

Next: True count and betting ↓
Card 0 / 20+1: 2–6 · 0: 7–9 · −1: 10–A
Press Next card
15 / 16 · Advanced: card counting

True count and betting

A running count of +6 means more with one deck left than with five. Divide by the decks left to get the , then bet more when it's high. That range is your .

Going deeper

Each true count point is worth roughly half a percent to the player, so the edge turns in your favour at about +1. Counters judge decks left by eye from the discard tray, to the nearest half deck. How deep the dealer deals before shuffling () decides how often good counts come up.

Next: Index plays ↓
Running +6 ÷ 3 decks leftTrue count +2
True count+2running ÷ decks left
Bet2×the table minimum

The same running count means more when fewer decks are left. A simple ramp: 1 unit up to a true count of +1, then 2, 4, 6 and 8 units at +2, +3, +4 and +5.

16 / 16 · Advanced: card counting

Index plays

At some counts the best move changes: 16 against a 10 becomes a stand at a true count of 0 or more, and insurance becomes worth it at +3. These are . Slide the count and watch the moves change.

Going deeper

The best-known set is called the Illustrious 18. Together they add only a little compared with a good bet spread, so learn them last. Practise them in the index drill.

Practise counting at a table →
At a true count of 0Index plays
HandDealerIndexPlay
InsuranceA+3No insurance
16100Stand
1510+4Hit
10,105+5Stand
10,106+4Stand
1010+4Hit
123+2Hit
122+3Hit
11A+1Hit
92+1Hit
10A+4Hit
97+3Hit
169+5Hit
132-1Stand
1240Stand

At or above the index, make the first move; below it, the other. Learn these only once your running count is quick and accurate: the bet spread matters far more.