Yes, I've heard about this too.

A biotech friend of mine told me that if doggy, the man can shoot further and thus increase the chance of pregnancy. Others told me missionary with a pillow on your buttock will also help the flow of the sperm deeper into the women's body.

Not sure how much this is true. It only increase the chance of getting pregnant. It does not guarantee a child gender. Look at the Table that was posted on the other thread. It seem quite accurate for most of us as I remembered.