Fisher Yates unbiased, well performing shuffle: From http://spin.atomicobject.com/2014/08/11/fisher-yates-shuffle-randomization-algorithm/

FYShuffle.js

//PSEUDOCODE!!

function fisher_yates_shuffle(items):
  for(i in _.range(items.length)){
    var randomIndex = random.randint(i, len(items)-1)
    temp = items[randomIndex]
    items[randomIndex] = items[i]
    items[i] = temp
  }
  return items
}