blackjack-gui

blackjack-gui

Single-player blackjack including graphical and command line interfaces, written in Python. Can be used to simulate games and to practise basic strategy and card counting.

Installation

blackjack-gui requires Python 3.10 or newer and uses tkinter. Make sure it's installed in your system:

$ sudo apt install python3-tk

or similar (otherwise, you'll see ModuleNotFoundError: No module named 'tkinter').

Then:

$ python3 -m venv venv
$ source venv/bin/activate
$ pip3 install blackjack-gui

Usage

blackjack [-h] [--cli] [--ai] [--count] [--bet BET] [--stack STACK]
    [--n-games N_GAMES] [--loglevel LOGLEVEL] [--cards CARDS]
    [--dealer-cards DEALER_CARDS] [--subset {hard,soft,pairs,hard/soft,soft/pairs}]
    [--rules {US,Helsinki}]

Options

Name	Default	Description
--cli	False	Use command line version.
--ai	False	If True, computer plays instead of you. Only with --cli.
--count	False	If True, ai uses card counting. Only with --cli and --ai. The bet spread: 1 unit (true count<1), 2 units (TC=1), 3 units (TC=3), 4 units (TC=4), 8 units (TC=5), 12 units (TC>=6).
--bet	10	Bet size (max 100).
--stack	200	Initial stack.
--n-games	10	Number of rounds to be played. Only with --cli.
--loglevel	DEBUG	Adjust amount of logging: DEBUG or INFO. Only with --cli.
--cards		Determine the first player cards, e.g. --cards=A,8,K. Shuffles the shoe after every hand. Multiple options (one will be randomly selected) can be defined like this: "A,7;9,9;10,2".
--subset		Instead of --cards, practice with one of the subsets: hard, soft, pairs, hard/soft, or soft/pairs
--dealer-cards		Determine the first dealer cards. Useful for testing.
--rules	US	Rules to be used. Can be Helsinki or US. See the basic strategy charts below.

Examples

Open the GUI version with Casino Helsinki Rules:

$ blackjack

With US rules:

$ blackjack --rules US

With the default settings, play 10 rounds of blackjack with the command line interface:

$ blackjack --cli

Let the computer play perfect basic game and use card counting technique to bring down the house:

$ blackjack --cli --ai --count --n-games=100000 --loglevel=INFO

Simulate soft 19 starting hand only:

$ blackjack --cli --ai --n-games=10000 --loglevel=INFO --cards=A,8

Practise to play "hard" starting hands:

$ blackjack --subset hard

Rules

Blackjack rules vary depending on the casino. In this application they follow the rules of Casino Helsinki, explained in Finnish here, i.e.:

• 6 decks
• Blackjack pays 3 to 2
• Dealer must stand on soft 17
• Dealer peek is not in use
• Any two cards can be doubled
• Max. 4 hands can be achieved by splitting
• Doubling after splitting is allowed
• Aces can be split but they receive only one extra card
• Resplit of aces is allowed
• Early surrender is allowed but not against Ace
• A 7-7-7 with the first three cards (not in a split game) pays 3 to 1 directly

See overview of the most common rule variations here.

Optimal basic strategy for Casino Helsinki

• Note that 16 vs 10 with 3 or more cards = Stay
• 7,7 would be normally Surrender, but not in Helsinki because of the 7-7-7 rule

Optimal basic strategy for a typical U.S. casino

The rules in the U.S. typically include:

• Dealer must hit on soft 17
• Dealer peek is in use
• Late surrender is not available
• Re-splitting of Aces (RSA) is not available
• Doubling and splitting rules otherwise same as above
• 7-7-7 rule is not available

Rule-based deviations

There are a few deviations from the basic strategy, which depend on the specific combination of the table rules. For a detailed, rule-specific strategy, consult the Wizard of Odds Blackjack Strategy Calculator to identify the optimal basic strategy for each game configuration.

Count-based deviations

Card counting affects the basic strategy. The following deviations are implemented in blackjack-gui (I will slowly add more). Use "Coach mode" with "Include deviations" to verify your play!

Your Hand	Dealer's Upcard	Basic strategy	Deviation	Index
2-10	A	Don't take insurance	Take	+3
A	A	Don't take even money	Take	+3
16	10	Hit	Stand	0+
12	2	Hit	Stand	+3
12	3	Hit	Stand	+2
12	4	Stand	Hit	0-
A,4	4	Double	Hit	0-

Where 0- means any negative running count, 0+ means any positive running count, and +X means true count of X or greater.

Development

Install blackjack-gui with dev-dependencies from GitHub:

git clone https://github.com/tukiains/blackjack-gui
cd blackjack-gui/
python3 -m venv venv
source venv/bin/activate
pip3 install --upgrade pip
pip3 install .[dev,test]
pre-commit install

Run unit and integration tests:

pytest tests/unit.py
pytest tests/integration.py

Run pre-commit checks:

pre-commit run --all

Credits

• Card images sourced from Google's Vector Playing Cards.
• Basic strategy follows Wizard of Odds Blackjack Strategy Calculator.
• Deviations are based on A1 Blackjack, an excellent source of free and useful blackjack content.
• Inspiration drawn from Blackjack Apprenticeship the premier resource for serious card counters.

Licence

MIT