There exists a very popular idea about the importance of sexual position for the fertilization. Many people believe that some certain positions for sex increase the couple’s chances on getting pregnant. There is even an idea about the influence of sexual position on the future’s baby sex and personality. If the last one sounds doubtlessly ridiculous and does not even need explanations, the first two ideas have at least a little scientific ground. The believed dependence on the child’s sex on position is explained by some specific qualities of X- and Y-chromosome carrying spermatozoids. What about the chances on pregnancy?