Select a number at random based on the frequency that it randomly showed up.

random_selector.js

Array.prototype.frequency = function() {
    this.sort();
    var i = 0, array, count, item, first = this.slice(0);
    while(i < first.length) {
        count = 1; item = first[i]; array = i + 1;
        while(array < first.length && (array = first.indexOf(item, array)) !== -1) {
            count += 1; first.splice(array,1);
        }
        first[i] += ' : '+ count; i++;
    }
    return first;
}
var random = [];
for (var i = 0; i < 1000; i++) random.push(Math.round(Math.random() * 10));
var frequency = random.frequency(), largest, largest_count = 0;
for(var n in frequency) {
    var current = frequency[n];
    if(typeof frequency[n] === 'string') var current_count = current.replace(/.*: /,'');
    if(current_count - largest_count > 0) {
        largest = current; 
        largest_count = current_count;
    }
}
largest = largest.replace(/(\d*).*/,'$1').trim();