JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    Die A: <input type="text" id="die_a" length="300px" value="-10,8,14,15,16,17" /><br />
    Die B: <input type="text" id="die_b" length="300px" value="6,9,9,11,11,14" /><br />
    Simulations: <input type="number" id="sim_count" min=1 step=1 value=1000 />
    <br />
    <input type="button" onclick="runTest()" value="Simulate!" />
    <pre id="results">
    </pre>
</body>

JavaScript

function runTest() {
    // Clear the result field
    $('#results').empty();
    
    // Load the text fields by splitting the numbers on commas and converting the values to integers
    var die_a = $('#die_a').val().split(',').map(function(i) { return parseInt(i, 10); });
    var die_b = $('#die_b').val().split(',').map(function(i) { return parseInt(i, 10); });
    
    
    // Verify that the dice are of the correct number of sides
    var a_len = die_a.length;
    var b_len = die_b.length;
    
    if (a_len != b_len || a_len != 6 || b_len != 6) {
        $('#results').append("Error: both dice must have exactly 6 sides.\n");
        $('#results').append("Die A has " + a_len + " sides\n");
        $('#results').append("Die B has " + b_len + " sides\n");
        return;
    }
    
    
    // Verify that the dice have the correct side sum
    var a_sum = 0, b_sum = 0, i;
    for (i = 0; i < 6; i++) {
        a_sum += die_a[i];
        b_sum += die_b[i];
    }
    
    if (a_sum != 60 || b_sum != 60) {
        $('#results').append("Error: both dice must have a sum of 60.\n");
        $('#results').append("Die A has a sum of " + a_sum + "\n");
        $('#results').append("Die B has a sum of " + b_sum + "\n");
        return;
    }
    
    
    // Verify that the side values are between -10 <= X <= 100
    for (i = 0; i < 6; i++) {
        if (die_a[i] < -10 || die_a[i] > 100 || die_b[i] < -10 || die_b[i] > 100) {
            $('#results').append("Error: die side values must be between -10 and 100 inclusive\n");
            return;
        }
    }
    
    
    // The dice look good, time to simulate them against each other
    compareDice(die_a, die_b);
}


// Compare all 36 equally possible outcomes
//   from throwing both dice
function compareDice(die_a, die_b) {
    var a_score = 0, b_score = 0;
    var i, j;
    
    for (i = 0; i < 6; i++) {
        for (j = 0; j < 6; j++) {
            
            // If tied, neither gets points
            if (die_a[i]...