title: What is the probability distribution of the new tiles in 2048?
body: <p>This question is about the popular game <a href="http://gabrielecirulli.github.io/2048/" rel="nofollow">2048</a>. I am wondering about the details of the appearance of new tiles at each turn:</p>
  
  <ul>
  <li>Is it 50% twos and 50% fours?</li>
  <li>Is the probability of appearance evenly distributed on all free slots?</li>
  </ul>