I would like to know with what probability the number 4 appears in the grid of the game 2048. As well, is this probability the same at the beginning? I tried to find the original game’s source code, but I did not succeed.

**Answer**

Extracted from the source code (line 71) :

```
var value = Math.random() < 0.9 ? 2 : 4;
```

`Math.random()`

returns a number between 0 and 1. This code can be read as follows : *Is the pseudo-randomly generated number strictly less than 0.9? If yes the tile value is 2, if no the value is 4*. Assuming `Math.random()`

generates numbers with uniform probability over (0,1), the code implies a 90% chance of a 2, and 10% chance of a 4.

As for your second question: Yes, the probability is the same at the beginning. When the game starts 2 tiles are generated and their value randomized with the code above.

**Attribution***Source : Link , Question Author : yo’ , Answer Author : WizLiz*