Pig game

pig-game.js

const ITERATIONS_USED = 10_000;
const MAX_LIMIT = 10;
const DICE_FACES = 6;
const MAX_DIGITS = 4;

function rollDice() {
	return Math.floor(1 + Math.random() * DICE_FACES);
}

function rollDiceUntilBreak(limit) {
	let diceRolls = 0;
	let total = 0;

	while (diceRolls < limit) {
		const result = rollDice();
		diceRolls++;

		if (result === 1) {
			return 0;
		} else {
			total += result;
		}
	}

	return total;
}

function burstRounds(limit, iterations) {
	let total = 0;
	for (let i = 0; i < iterations; i++) {
		const result = rollDiceUntilBreak(limit);
		total += result;
	}

	return total / iterations;
}

function predictAverage(limit) {
	return Math.pow(5 / 6, limit) * (limit * 4);
}

function stripDigits(number) {
	return parseFloat(number).toFixed(MAX_DIGITS);
}

for (let limit = 1; limit < MAX_LIMIT; limit++) {
	const average = stripDigits(burstRounds(limit, ITERATIONS_USED));
	const predicted = stripDigits(predictAverage(limit));

	console.log(
		`For dice rolled ${limit} times, the average score is: ${stripDigits(
			average
		)}, while the predicted average is: ${stripDigits(
			predicted
		)}, with a difference of: ${stripDigits(average - predicted)}`
	);
}