This project is in beta.
Clone the repo, then:
Test: (may take up to two minutes)
./gradlew checkInstall:
./gradlew installDistThe executable should then be built in build/install/Blackjack/bin
Get help:
./blackjack -?Solve for the house edge and gives accurate strategy advice for a given rule set (assumes a console width of ~100 characters):
./blackjack --decks=4 --hsa=false --double-after-split=false --surrender=early --no-hole-card
(...description of rule set...)
HARD HANDS
Dealer Up Card
Player Cards 2 3 4 5 6 7 8 9 10 A
2, 3 H H H H H H H H H R
S S S S S S S S R H
2, 4 H H H H H H H H H R
S S S S S S S S R H
2, 5 H H H H H H H H H R
S S S S D S S S R H
3, 4 H H H H H H H H H R
S S S S D S S S R H
2, 6 H H H H H H H H H H
D D D D D D D S R R
3, 5 H H H H H H H H H H
D D D D D D D S R R
2, 7 H D D D D H H H H H
D H H H H D D D R R
3, 6 H D D D D H H H H H
D H H H H D D D R R
4, 5 H D D D D H H H H H
D H H H H D D D R R
2, 8 D D D D D D D D H H
H H H H H H H H D D
3, 7 D D D D D D D D H H
H H H H H H H H D D
4, 6 D D D D D D D D H H
H H H H H H H H D D
2, 9 D D D D D D D D D D
H H H H H H H H H H
3, 8 D D D D D D D D D D
H H H H H H H H H H
4, 7 D D D D D D D D D D
H H H H H H H H H H
5, 6 D D D D D D D D D D
H H H H H H H H H H
2, 10 H H S S S H H H H R
S S H H H S S S R H
3, 9 H H S S S H H H H R
S S H H H S S S R H
4, 8 H H S S S H H H H R
S S H H H S S S R H
5, 7 H H S S S H H H H R
S S H H H S S S R H
3, 10 S S S S S H H H H R
H H H H H S S S R H
4, 9 S S S S S H H H H R
H H H H H S S S R H
5, 8 S S S S S H H H H R
H H H H H S S S R H
6, 7 S S S S S H H H H R
H H H H H S S S R H
4, 10 S S S S S H H H R R
H H H H H S S S H H
5, 9 S S S S S H H H R R
H H H H H S S S H H
6, 8 S S S S S H H H R R
H H H H H S S S H H
5, 10 S S S S S H H H R R
H H H H H S S S H H
6, 9 S S S S S H H H R R
H H H H H S S S H H
7, 8 S S S S S H H H R R
H H H H H S S S H H
6, 10 S S S S S H H H R R
H H H H H S S S H H
7, 9 S S S S S H H H R R
H H H H H S S S H H
7, 10 S S S S S S S S S R
H H H H H H H H R S
8, 9 S S S S S S S S S R
H H H H H H H H R S
8, 10 S S S S S S S S S S
H H H H H H H H R R
9, 10 S S S S S S S S S S
H H H H H H H H R R
SOFT HANDS
Dealer Up Card
Player Cards 2 3 4 5 6 7 8 9 10 A
A, 2 H H H D D H H H H H
D D D H H D D D R R
A, 3 H H H D D H H H H H
D D D H H D D D R R
A, 4 H H D D D H H H H H
D D H H H D D D R R
A, 5 H H D D D H H H H H
D D H H H D D D R R
A, 6 H D D D D H H H H H
D H H H H D D D S R
A, 7 D D D D D S S H H H
S S S S S D H S S S
A, 8 S S S S D S S S S S
D D D D S D D H H H
A, 9 S S S S S S S S S S
D D D D D D D D H H
A, 10 S S S S S S S S S S
S S S S S S S S S S
SPLIT HANDS
Dealer Up Card
Player Cards 2 3 4 5 6 7 8 9 10 A
2, 2 H H Y Y Y Y H H H R
Y Y H H H H Y Y R H
3, 3 H H Y Y Y Y H H H R
Y Y H H H H Y Y R H
4, 4 H H H H H H H H H H
D D D D D D Y Y R R
5, 5 D D D D D D D D H H
H H H H H H H H D D
6, 6 H Y Y Y Y H H H H R
Y H S S S Y Y S R H
7, 7 Y Y Y Y Y Y H H R R
S S S S S H Y S H H
8, 8 Y Y Y Y Y Y Y Y R R
S S S S S H H H Y Y
9, 9 Y Y Y Y Y S Y Y S S
S S S S S Y S S Y Y
10, 10 S S S S S S S S S S
Y Y Y Y Y Y Y Y Y Y
A, A Y Y Y Y Y Y Y Y Y Y
H H H H D H H H H H
The house edge is -0.0590% The program store strategy data in files; if the file is not found for a given rule set, it will calculate the data fresh based on a given rule set.
Currently only available for composition-dependent strategy.
Rules theRules = new Rules(4);
theRules.setAccuracy(Rules.CACHE_ACCURACY); //Controls calculation speed and accuracy
theRules.setHitSplitAces(true);
theRules.setHitOn17(false);
theRules.myDoubleRules.setOnlyTenAndEleven(true);
Strategy myStrategy = new Strategy(theRules, Strategy.Skill.COMP_DEP);
//Checked exceptions -- IOException and NoRecommendationException
double houseEdge = myStrategy.getHouseEdge();The API does not contain the idea of chips or amount wagered (or any graphics).
/* Same set up as above, then: */
Shoe myShoe = new Shoe(theRules.getNumberOfDecks());
State myState = new State(myShoe.drawRandom(), myShoe.drawRandom(), myShoe.drawRandom());
//To see what actions are possible:
boolean splitPossible = theRules.isPossible(Action.SPLIT, myState);
boolean doublePossible = theRules.isPossible(Action.DOUBLE, myState);
//Get the best action, assuming that the Shoe was pristine before this hand was dealt.
//Checked exceptions -- IOException and NoRecommendationException
Action bestAction = myStrategy.findBestAction(myState, theRules);
//Does a fresh calculation based on the current contents of the Shoe.
myStrategy.setStrategyType(Strategy.Skill.PERFECT);
//Checked exceptions -- IOException and NoRecommendationException
Action optimalAction = myStrategy.findBestAction(myState, theRules, myShoe);The Javadocs in the State class have more information about how to play through a hand.
Results of this calculator matched those of other blackjack calculators, apart from split results (which tend to vary from calculator to calculator). If you find any discrepancy between the results here and those of other calculators, please file an issue.
Supported rule sets include:
- 1-8 decks
- Variable blackjack payback amount
- Early surrender / late surrender
- No hole card
- Resplit allowed (Multiple resplits not supported)
- Resplit aces (0-1 times)
- Hit split aces
- Dealer hit on soft 17
- Double on: 9-11, 10-11, any two cards, any 2-card hard total, any number of cards, on split aces
Solved rule sets can be stored on disk so that calculations do not need to be repeated. A standard rule set may take 5-15 seconds to calculate. If the dealer probability cache is used, then the first rule set will take much longer but then subsequent rule sets will be faster.
- The house edge is currently only calculated for composition-dependent strategies
- Only one resplit is allowed
- Complicated surrender/double rules are not implemented
- Standard deviation, effect of shoe depth, other probabilities not calculated
- Split calculations are not optimized
The project is in beta because of the shoddy state of project organization, so if you are in need of reliable results you should go to the tried-and-true calculators.
The project's API is usable, but the code needs clean-up.
- Migrate tests to JUnit, refactor match best practices, check code coverage, add test cases where applicable
- Refactor program to follow best practices
- Change code architecture where appropriate, refactor overly long classes/functions
- Use third-party libraries where appropriate
- Remove dead/duplicate/deprecated code
- Expose more functionality through the command line(different BJ payback amounts, EV for given hands, etc.)
- Avoid breaking API changes if possible
- Create web front-end
- Store results in database to make data more accessible
- Add capabilities to match other calculators
Yes! They are welcome! Please let me know what you want to work on. The most important thing to do now is to refactor the tests: migrate them to JUnit, remove useless ones, and add unit tests where appropriate. Once that is done, then there are scores of TODOs -- just grab one and ping me and refactor away. Bug fixes and suggestions for API and documentation improvements are always welcome. Also please see the issues list.
GNU
This is the first program of any length I wrote; I stopped development in August 2014 and restarted in Feb 2016. The code needs serious refactoring (for several reasons -- I did it on a lark, not expecting to publish it; I was inexperienced when I wrote it; and I purposely used no external libraries.). It's in Java so it will never compare to other calculators in terms of speed.
There is nothing new in this calculator in terms of algorithms. It uses a cache to speed up calculation of dealer hand results and approximates split hand results.
Thanks to all those who have solved this problem before, especially those who posted results online: John A. Nairn, the Wizard of Odds, Casino Vérité Software, bjstrat.net. I hope that this calculator will one day be as good as the already existing ones.