README.md

Blackjack Simulator

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

Features

• Simulator mode for computing EV given some table conditions (10M hands / second)
• Game mode 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

npm install -g @blackjacktrainer/blackjack-simulator

blackjack-simulator simulate --help

Override the number of CPU cores used:

CORES=1 blackjack-simulator simulate

Game mode

blackjack-simulator game --help

See it live as a web app here.

Build and run locally

npm install
nvm use --install
NODE_ENV=development npm run build
./bin/cli.js

Use as a library (simulator mode)

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, 2000, 4000, 8000, 16000],
  playerSpots: [1, 1, 1, 1, 1],
  playerTablePosition: 1,
  playerBankroll: 1000 * 10 ** 7,
  playerWongOutTrueCount: null,

  // Table rules
  allowDoubleAfterSplit: true,
  allowLateSurrender: true,
  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;
  bankrollRqd: number;
  bankrollVariance: number;
  handsLost: number;
  handsPlayed: number;
  handsPushed: number;
  handsWon: number;
  hoursPlayed: number;
  riskOfRuin: number;
  timeElapsed: number;
}

Use as a library (game mode)

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.serialize(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:

{
  game.state.step === GameStep.WaitingForPlayInput && (
    <>
      <button data-action="s">Stand (S)</button>
      <button data-action="h">Hit (H)</button>
      <button data-action="d">Double (D)</button>
      <button data-action="r">Surrender (R)</button>
      <button data-action="p">Split (P)</button>
    </>
  );
}
{
  game.state.step === GameStep.WaitingForInsuranceInput && (
    <>
      <button data-action="n">No (N)</button>
      <button data-action="y">Yes (Y)</button>
    </>
  );
}
{
  game.state.step === GameStep.WaitingForNewGameInput && (
    <>
      <button data-action="d">Deal (press any key)</button>
    </>
  );
}