Blackjack

Blackjack stands apart in the casino. It's one of the few games where player decisions genuinely matter, where skill reduces the house edge, and where advantage play is mathematically possible. The goal is simple: beat the dealer by getting closer to 21 without busting. But beneath that simplicity lies a game of probability, strategy, and risk management. Played correctly, blackjack offers better odds than almost any other casino game. Played poorly, those odds evaporate.

How to Play Blackjack
Card Values and Hand Rankings
Player Actions
Basic Strategy
House Edge and Rules Variations
Card Counting Basics
Common Mistakes

How to Play Blackjack {#how-to-play}

The Objective

Beat the dealer by having a higher hand value without exceeding 21.

The Deal

Players place bets
Each player receives 2 cards (face up)
Dealer receives 2 cards (one up, one down)
Players act on their hands
Dealer reveals hole card and plays
Hands are compared, bets settled

Winning and Losing

Outcome	Result
Player closer to 21	Player wins 1:1
Player has blackjack	Player wins 3:2
Dealer closer to 21	Player loses
Tie (push)	Bet returned
Player busts (over 21)	Player loses immediately
Dealer busts	Player wins (if not busted)

The Dealer's Rules

The dealer has no decisions—they follow fixed rules:

Dealer Hand	Action
16 or less	Must hit
17 or more	Must stand (usually)
Soft 17 (A+6)	Varies by casino

H17 (hit soft 17): +0.2% house edge S17 (stand soft 17): Better for player

Card Values and Hand Rankings {#card-values}

Card Values

Card	Value
2-10	Face value
J, Q, K	10
Ace	1 or 11

Hard vs Soft Hands

Hand Type	Definition	Example
Hard	No ace, or ace counts as 1	K-7 = hard 17
Soft	Ace counts as 11	A-6 = soft 17

Soft hands can't bust with one hit—the ace converts to 1.

Hand Rankings

Hand	Value	Special
Blackjack	21	Ace + ten-value, 2 cards only
21	21	3+ cards
Under 21	Face value	—
Bust	Over 21	Automatic loss

Blackjack beats 21: A-K beats 5-6-K-5.

Blackjack Payouts

Type	Payout	On $10 Bet
3:2 (traditional)	1.5×	$15
6:5 (avoid!)	1.2×	$12
Even money	1×	$10

Always play 3:2 tables. The 6:5 payout adds 1.4% to house edge.

Player Actions {#actions}

Hit

Take another card.

When to hit:

Low hand value vs. dealer's strong upcard
Soft hands with room to improve

Stand

Keep current hand, end turn.

When to stand:

Strong hand (17+) against any dealer card
Hard 12-16 against dealer's weak upcard (4-6)

Double Down

Double your bet, receive exactly one more card.

\text{EV (Double)} = 2 \times \text{Bet} \times P(\text{Win}) - 2 \times \text{Bet} \times P(\text{Lose})

When to double:

11 vs. dealer 2-10
10 vs. dealer 2-9
Soft 16-18 vs. dealer 4-6

Split

Divide a pair into two separate hands (doubles the bet).

Pair	Split?	Reasoning
A-A	Always	Two chances for 21
8-8	Always	16 is terrible, 8s are playable
10-10	Never	20 is too strong to break up
5-5	Never	10 is ideal for doubling
4-4	Usually no	8 is playable

Surrender

Give up half your bet to forfeit the hand.

When to surrender:

Hard 16 vs. dealer 9, 10, or A
Hard 15 vs. dealer 10

Surrender reduces losses on hopeless hands.

Insurance

Side bet when dealer shows ace—pays 2:1 if dealer has blackjack.

\text{Insurance EV} = 0.3077 \times 2 - 0.6923 \times 1 = -0.077 = -7.7\%

Never take insurance (unless counting cards).

Basic Strategy {#basic-strategy}

What Is Basic Strategy?

The mathematically optimal decision for every hand combination, calculated by computer simulation of millions of hands.

Hard Hands Strategy

Your Hand	Dealer 2-6	Dealer 7-A
8 or less	Hit	Hit
9	Double vs 3-6, else Hit	Hit
10	Double	Double vs 2-9, Hit vs 10-A
11	Double	Double
12	Stand vs 4-6, else Hit	Hit
13-16	Stand	Hit
17+	Stand	Stand

Soft Hands Strategy

Your Hand	Dealer 2-6	Dealer 7-A
A-2, A-3	Double vs 5-6, else Hit	Hit
A-4, A-5	Double vs 4-6, else Hit	Hit
A-6	Double	Hit
A-7	Double vs 3-6, Stand vs 2, 7, 8	Hit vs 9-A
A-8	Stand (Double vs 6)	Stand
A-9	Stand	Stand

Pair Splitting Strategy

Pair	Split?
A-A	Always
2-2, 3-3	vs 2-7
4-4	vs 5-6 only (or never)
5-5	Never (double instead)
6-6	vs 2-6
7-7	vs 2-7
8-8	Always
9-9	vs 2-6, 8-9 (stand vs 7, 10, A)
10-10	Never

\text{House Edge} \approx 0.5\%

Rules That Affect House Edge

Rule	Effect on House Edge
3:2 vs 6:5 blackjack	+1.39% (6:5 is worse)
Dealer hits soft 17	+0.22%
No double after split	+0.14%
No re-splitting aces	+0.08%
8 decks vs 1 deck	+0.61%
Surrender allowed	-0.08%
Double on any 2 cards	-0.25%

Typical House Edges by Game Type

Game Type	Approximate Edge
Single deck, 3:2, good rules	0.2%
6 deck, 3:2, standard rules	0.5%
6 deck, 3:2, H17	0.7%
8 deck, 6:5, H17	2.0%
"Party" blackjack variants	1.5-3.0%

Rules to Seek

Good Rule	Bad Rule
3:2 payout	6:5 payout
Dealer stands on soft 17	Dealer hits soft 17
Double after split	No DAS
Late surrender	No surrender
Fewer decks	8 decks

Card Counting Basics {#card-counting}

How Card Counting Works

Track the ratio of high cards (10s, aces) to low cards remaining in the deck.

\text{High Cards} \uparrow = \text{Player Advantage} \uparrow

High cards favor the player because:

More blackjacks (which pay 3:2)
Better doubling outcomes
Dealer busts more often

The Hi-Lo Count

Cards	Count Value
2-6	+1
7-9	0
10-A	-1

Running count: Sum of all cards seen True count: Running count ÷ decks remaining

Betting with the Count

True Count	Action
-1 or lower	Minimum bet or leave
0	Minimum bet
+1	2× minimum
+2	4× minimum
+3+	Maximum bet

Expected Edge from Counting

\text{Player Edge} \approx 0.5\% \times (\text{True Count} - 1)

True Count	Approximate Edge
+1	0% (break-even)
+2	+0.5%
+3	+1.0%
+4	+1.5%

Reality of Card Counting

Myth	Reality
"Easy money"	Requires 200+ hours to master
"Big profits"	1-2% edge with high variance
"Illegal"	Legal but casinos ban counters
"Anyone can do it"	Few have discipline for tedious grind

Bankroll Requirements for Counting

\text{Risk of Ruin} = e^{-\frac{2 \times \text{Edge} \times \text{Bankroll}}{\text{Bet Variance}}}

For 1% risk of ruin with 1% edge: need 300-500 max bet units.

Common Mistakes {#mistakes}

Mistake 1: Playing 6:5 Tables

Payout	1,000 Blackjacks at $10	Difference
3:2	$15,000	—
6:5	$12,000	-$3,000

6:5 costs you $3 per blackjack per$ 10 bet.

Mistake 2: Taking Insurance

Decision	Expected Value
Take insurance	-7.7% of insurance bet
Decline	$0

Insurance is a sucker bet.

Mistake 3: "Playing Hunches"

Action	House Edge
Perfect basic strategy	0.5%
"I feel lucky" plays	2-4%

Hunches don't know probability.

Strategy	EV Change
Increase bets after losses	None (same house edge)
Proper bankroll management	Survive variance

Online vs. Live Blackjack {#online}

Standard Online Blackjack

Factor	Detail
Decks	Usually 6-8
Shuffling	Every hand (RNG)
Speed	Very fast
Card counting	Impossible
House edge	Standard (0.5%+)

Live Dealer Blackjack

Factor	Detail
Decks	8 (usually)
Shuffling	After ~50% penetration
Speed	Moderate
Card counting	Theoretically possible, practically difficult
House edge	Standard

Blackjack Variants to Avoid

Variant	Issue
Blackjack Switch	Complex strategy, higher edge
Super Fun 21	Worse payouts
Spanish 21	No 10s in deck
Free Bet Blackjack	Push on dealer 22

Stick to classic blackjack.

Blackjack Calculator - Hand-by-hand analysis
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Evgeny Volkov

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