https://github.com/mhluska/blackjack-simulator

🃏 Realistic blackjack simulator (practice card counting using Hi-Lo and calculate EV for any table conditions)
https://github.com/mhluska/blackjack-simulator

blackjack blackjack-game blackjack-simulator cli javascript multiprocessing nodejs simulator typescript

Last synced: about 2 months ago
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🃏 Realistic blackjack simulator (practice card counting using Hi-Lo and calculate EV for any table conditions)

• Host: GitHub
• URL: https://github.com/mhluska/blackjack-simulator
• Owner: mhluska
• License: mit
• Created: 2020-06-08T16:38:22.000Z (about 6 years ago)
• Default Branch: master
• Last Pushed: 2026-04-18T18:21:58.000Z (about 2 months ago)
• Last Synced: 2026-04-18T20:26:23.072Z (about 2 months ago)
• Topics: blackjack, blackjack-game, blackjack-simulator, cli, javascript, multiprocessing, nodejs, simulator, typescript
• Language: TypeScript
• Homepage: https://blackjacktrainer.app
• Size: 2.34 MB
• Stars: 66
• Watchers: 1
• Forks: 21
• Open Issues: 7
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE

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README

          


  



# Blackjack Simulator







> Practice card counting using Hi-Lo and calculate EV for any table conditions

## Features

- Simulator mode for computing EV given any table conditions

- [Game mode](https://blackjacktrainer.app) for practicing basic strategy and card counting with hints

- No package dependencies

- Runs in any JS environment (CLI, browser, React Native app etc)

- Multi-core support in Node

## Usage

### Simulator mode

```sh

npm install -g @blackjacktrainer/blackjack-simulator

```

```sh

blackjack-simulator simulate --help

```

Override the number of CPU cores used:

```sh

CORES=1 blackjack-simulator simulate

```

### Game mode

```sh

blackjack-simulator game --help

```

See it live as a web app [here](https://blackjacktrainer.app).

### Build and run locally

```sh

npm install

nvm use --install

NODE_ENV=development npm run build

./bin/cli.js

```

### Use as a library (simulator mode)

```js

import { Simulator } from '@blackjacktrainer/blackjack-simulator';

// Default settings:

const settings = {

  debug: false,

  // Simulator-only settings:

  hands: 10 ** 7,

  // Can be one of:

  // 'basic-strategy': play perfect basic strategy

  // 'basic-strategy-i18': play perfect basic strategy plus illustrious 18

  // 'basic-strategy-i18-fab4': play perfect basic strategy plus illustrious 18 + fab 4

  playerStrategy: 'basic-strategy-i18-fab4',

  playerBetSpread: [1000, 1000, 4000, 7000, 10000],

  playerSpots: [1, 1, 1, 1, 1],

  playerTablePosition: 1,

  playerBankroll: 1000 * 10 ** 7,

  playerWongOutTrueCount: -Infinity,

  // Table rules

  allowDoubleAfterSplit: true,

  allowLateSurrender: false,

  allowResplitAces: false,

  blackjackPayout: '3:2',

  deckCount: 2,

  hitSoft17: true,

  maxHandsAllowed: 4,

  maximumBet: 1000 * 100,

  minimumBet: 1000,

  playerCount: 1,

  penetration: 0.75

};

const simulator = new Simulator(settings);

const result = simulator.run();

```

Result contains the following data:

```

{

  amountEarned: number;

  amountWagered: number;

  bankrollMean: number;

  bankrollVariance: number;

  handsLost: number;

  handsPlayed: number;

  handsPushed: number;

  handsWon: number;

  hoursPlayed: number;

  riskOfRuin: number;

  timeElapsed: number;

}

```

### Use as a library (game mode)

```js

import {

  Event,

  Game,

  GameStep,

  PlayerInputReader

} from '@blackjacktrainer/blackjack-simulator';

// Default settings:

const settings = {

  autoDeclineInsurance: false,

  disableEvents: false,

  checkDeviations: false,

  // Can be one of 'default', 'pairs', 'uncommon', 'deviations'. If the mode is set to 'deviations', `checkDeviations`

  // will be forced to true.

  mode: 'default',

  debug: false,

  playerBankroll: 1000 * 10 ** 7,

  playerTablePosition: 1,

  playerStrategyOverride: {},

  // Table rules

  allowDoubleAfterSplit: true,

  allowLateSurrender: false,

  allowResplitAces: false,

  blackjackPayout: '3:2',

  deckCount: 2,

  hitSoft17: true,

  maxHandsAllowed: 4,

  maximumBet: 1000 * 100,

  minimumBet: 1000,

  playerCount: 1,

  penetration: 0.75

};

const game = new Game(settings);

// In a real app, this will likely be a React-redux store or a Vuex store.

const state = {};

// Called when any game state changes. `name` will be one of the following:

//

// - focusedHand

// - sessionMovesCorrect

// - sessionMovesTotal

// - playCorrection

// - step

// - shoe

// - discardTray

// - dealer

// - player

// - handWinner

game.on(Event.Change, (name, value) => {

  state[name] = value;

});

game.on(Event.Shuffle, () => {

  console.log('End of shoe, cards shuffled!');

});

// Emitted when the game wants to save optional game statistics.

// `entityName` can be one of `hand-result` or `move`.

// `data` is a plain object with values to save to the backend.

game.on(Event.CreateRecord, (entityName, data) => {

  fetch(`/api/v1/${entityName}`, {

    method: 'POST',

    body: JSON.stringify(data),

    headers: {

      Accept: 'application/json',

      'Content-Type': 'application/json'

    }

  });

});

function stepGame(game, playerInputReader, input) {

  const step = game.step(input);

  if (

    ![

      GameStep.WaitingForPlayInput,

      GameStep.WaitingForInsuranceInput,

      GameStep.WaitingForNewGameInput

    ].includes(step)

  ) {

    return Promise.resolve();

  }

  return new Promise((resolve) => playerInputReader.readInput(resolve));

}

async function runGame(game) {

  game.betAmount = 10 * 100;

  const playerInputReader = new PlayerInputReader();

  let input;

  while (true) {

    input = await stepGame(game, playerInputReader, input);

  }

}

runGame(game);

```

`PlayerInputReader.readInput` listens for a `click` or `keypress`

event on `document.body`. Your DOM just has to declare the following buttons

somewhere for user interaction:

```jsx

{

  game.state.step === GameStep.WaitingForPlayInput && (

    <>

      Stand (S)

      Hit (H)

      Double (D)

      Surrender (R)

      Split (P)

    >

  );

}

{

  game.state.step === GameStep.WaitingForInsuranceInput && (

    <>

      No (N)

      Yes (Y)

    >

  );

}

{

  game.state.step === GameStep.WaitingForNewGameInput && (

    <>

      Deal (press any key)

    >

  );

}

```

## Performance

Tested on Apple M2 Max, Node v24.3, default settings (2-deck H17, I18 + Fab 4 deviations, bet spread).

| Cores | Hands | Time | Hands/sec |

|---|---|---|---|

| 1 | 100M | ~53s | ~1.9M |

| 4 | 1B | ~134s | ~7.5M |

| 12 | 1B | ~65s | ~15M |