Masterjun3 | [TAS] 2048 in 881 moves @Masterjun3 | Uploaded July 2020 | Updated October 2024, 10 hours ago.
Remember that game from the year 2014? You slide number tiles and equal ones combine upon collision. After each move a new tile appears: either a [2] (90% chance) or a [4] (10% chance). The goal is creating the 2048 tile.

The theory behind this game is pretty simple. No matter how you slide, the total sum on the board stays the same and only increases by either 2 or 4 with the new tile. A total board sum of 2048 thus requires at least 512 tile spawns, so 510 moves (two tiles spawn at the beginning). After that, at least another 9 moves are required to combine tiles to the 2048 tile.

With impossible luck - getting only 4-tiles to spawn - the minimum
number of moves is 519.
With impossible bad luck - getting only 2-tiles to spawn - the minimum number of moves is 1032.

The only real optimization in this TAS is finding the optimal seed and making sure the final moves are positioned as to not waste a move.

For this TAS to be authentic, I had to recreate the Math.random() function of a browser, that is, of a JavaScript engine used by a browser. I decided to recreate it from the V8 engine. After that I ran a search for seed that spawned the most 4-tiles with an extra rule valuing seeds more highly when the total board sum goes from 2044 to 2048 with a 4-tile spawn.

The seed I used was 7771287229.
Of the important 874 tile spawns, I got 724 2-tiles and 150 4-tiles, which equals 82.84% and 17.16% (the game aims for 90% and 10%).
This roughly equals a 1 in 17066527652 chance.

The video shows the run twice, first at 60 moves per second, and then at 10 moves per second.

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Game: 2048 - play2048.co
Music: Eternal Forest by Red&Green - youtu.be/ml9UFvxHBQE