Yes, Calculation is 100% genetical fact. Such as a dog can not calculate position.
No, for human level. Calculation is nothing but thinking on secret knowledge. When you will figure it out, you are not ordinary person.
Suppose you [OP] are a clever boy but you are not good at calculation, cause you do not know the grammar of thinking. Only a clever boy can put such kind of thread within 3 days of after account opening.
I agree that many players are lucky enough to be able to play blindfold chess practically from the first time they learn how the pieces move.
But you think because I wasn't born with the ability I can't learn it?
CHALLENGE ACCEPTED