Each turn, one 2 tile is added, and other tiles may be combined. So you can derive the move count by adding together the numbers on all the visible tiles and dividing by 2.
This is inaccurate, because you have a 10% chance of getting a 4 tile added instead of a 2. That part makes the game tricky, because otherwise you could optimize every solution like an algorithm without ever losing.
Oh, huh, I didn't even realize it was doing that. Even so, the move count will still be roughly proportional to the sum of the board (plus or minus some random variation), won't it?
This would be cool. I think winning in the fewest moves would be the most impressive. i.e. how few tiles you 'waste'. Though winning with the lowest score may approximate this.
