I know that shinies are calculated based on 4 numbers: 2 random and your normal + secret trainer ID.
Example:
Your Trainer ID: 00301
Your Secret ID: 00149
In binary this is:
Normal: 0000000100101101
Secret: 0000000010010101
Then the numbers are XOR'd, meaning they are lined up and the digits compared. If exactly one of them is a 1, then that becomes 1, if they are both 1 or both 0, then that digit becomes 0.
So XOR'ing the above numbers gets: 0000000110111000
Then 2 random numbers between 0 and 65536 are generated, and then XOR'd:
Example:
Random #1: 1110110101110010
Random #2: 1110100010101010
XOR'ing: 0000010111011000
And then the #s that resulted from XOR'ing are XOR'd again:
0000000110111000
0000010111011000
Final result: 0000010001100000 or 1,120
This final number is greater than 8, so the pkmn is not shiny.
If the final number had been less than or equal to 8, it would have been shiny.
Now about this:
Because 2 of the numbers (the 2 ID's) are set throughout the game, does that mean that certain ID combinations would cause a lower or higher chance (or possibly zero chance) of finding a shiny?
Example:
Your Trainer ID: 00301
Your Secret ID: 00149
In binary this is:
Normal: 0000000100101101
Secret: 0000000010010101
Then the numbers are XOR'd, meaning they are lined up and the digits compared. If exactly one of them is a 1, then that becomes 1, if they are both 1 or both 0, then that digit becomes 0.
So XOR'ing the above numbers gets: 0000000110111000
Then 2 random numbers between 0 and 65536 are generated, and then XOR'd:
Example:
Random #1: 1110110101110010
Random #2: 1110100010101010
XOR'ing: 0000010111011000
And then the #s that resulted from XOR'ing are XOR'd again:
0000000110111000
0000010111011000
Final result: 0000010001100000 or 1,120
This final number is greater than 8, so the pkmn is not shiny.
If the final number had been less than or equal to 8, it would have been shiny.
Now about this:
Because 2 of the numbers (the 2 ID's) are set throughout the game, does that mean that certain ID combinations would cause a lower or higher chance (or possibly zero chance) of finding a shiny?