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betaBinomialFoldPosterior

Conjugate Beta–Binomial update on fold frequency.

betaBinomialFoldPosterior(priorAlpha: number, priorBeta: number, folds: number, calls: number): BetaBinomialFoldPosterior

Import​

const poker = require('poker-calculations');

ESM (Node):

import { createRequire } from 'module';
const require = createRequire(import.meta.url);
const poker = require('poker-calculations');

When to use​

Maintain a Bayesian belief about how often a player (or population) folds, updating as you observe folds and calls. Prior is Beta(priorAlpha, priorBeta); observations add folds to α and calls to β.

How to use​

const poker = require('poker-calculations');

const priorAlpha = 2;
const priorBeta = 2;
const foldsObserved = 7;
const callsObserved = 3;

const post = poker.betaBinomialFoldPosterior(
  priorAlpha,
  priorBeta,
  foldsObserved,
  callsObserved,
);

console.log(post);
// { alpha: 9, beta: 5, posteriorMean: 9/14 }

Returns​

BetaBinomialFoldPosterior — { alpha: number, beta: number, posteriorMean: number } where posteriorMean = alpha / (alpha + beta) after the conjugate update.