[pedrocr]

Interesting. It seems the solution I and a couple of people more came up with of keeping the top value in a corner isn't being used. It's amazing how it's able to keep the large numbers together throughout the game.

The gameplay is much more interesting but it seems that getting from 1024 to 2048 is much harder this way, probably because the randomness accumulates over time making the depth search unreliable. The more structured solution accumulates much less risk so has some margin to deal with this.