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exactHeroCategoryJointFlopToRiver

Joint distribution of hero hand category on the turn and category on the river after enumerating all turn/river runouts from a fixed flop.

exactHeroCategoryJointFlopToRiver(heroHoleCards: CardInput, flopThree: CardInput, knownDead?: CardInput): { jointMatrix: Float64Array }

jointMatrix has length 81; index catTurn * 9 + catRiver for categories 0..8. See Packed card input.

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​

You need the exact flop→river category joint (not Monte Carlo) — for study charts, backend aggregation, or comparing how often hero improves or regresses by category on a fixed flop.

How to use​

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

const hero = ['Ah', 'Kh'];
const flop = ['Qh', 'Jh', '2c'];

const { jointMatrix } = poker.exactHeroCategoryJointFlopToRiver(hero, flop);

console.log('Matrix length:', jointMatrix.length);
console.log('P(turn cat 0, river cat 0):', jointMatrix[0]);
console.log('Sum (should be ~1):', [...jointMatrix].reduce((a, b) => a + b, 0));

The second argument must be exactly three flop cards (not a four-card turn board). Optional knownDead removes extra cards from the deck before enumeration.

Return type​

{ jointMatrix: Float64Array } — length 81, entries are probabilities summing to 1 over enumerated runouts.

See also​

exactHeroRunoutVulnerability · exactHeroEquityRunoutQuantiles · Tournament, runouts, and bots