If you want to conceive a boy, then choosing the right sexual position is very important.

In order to increase your chance of conceiving a boy, you should have intercourse in a position that allows deep penetration (for example doggy style), as deep penetration allows the sperm to be deposited closer to the egg.

Because male sperm are thought to be weaker than female sperm, they are less likely to be able to swim the greater distance to the womb than female sperm (which are stronger and more resilient than male sperm). However, male sperm are also thought to be faster swimmers than female sperm, giving them a speed advantage. So by using a deep penetration position, and decreasing the distance to the egg, male sperm are more likely to get to the egg before the female sperm, and the decreased distance gives them a much better chance of survival, increasing your chances of conceiving a baby boy.