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equityToWinningOddsAgainst

Book-style winning odds against: (1 − equity) / equity. Returns Infinity at equity === 0; 0 at equity === 1. Equity is clamped to [0, 1].

equityToWinningOddsAgainst(equity: number): number

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​

Use when a study tool or book quote gives equity but you want “3:1 against” style numbers (lose : win), or to label draw strength next to pot-odds display ratios. Pair with winningOddsAgainstToEquity to round-trip.

How to use​

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

const equity = 0.25; // 25% to win
const against = poker.equityToWinningOddsAgainst(equity);
console.log(against); // 3 — often read as "3:1 against"

// Round-trip
const back = poker.winningOddsAgainstToEquity(against);
console.log(back); // 0.25

console.log(poker.equityToWinningOddsAgainst(0)); // Infinity
console.log(poker.equityToWinningOddsAgainst(1)); // 0

Not the same as pot odds (potBeforeCall / toCall); this is purely equity ↔ book odds.

Returns number — (1 − equity) / equity for equity in (0, 1); Infinity at equity === 0; 0 at equity === 1. Input is clamped to [0, 1].

See also​

winningOddsAgainstToEquity · breakevenCallEquity · potOddsDisplayRatioFromBreakevenCallEquity