@sergio
Peolpe like me are realistic!! I appreciate that you put it into plain english for people like me

. Your theory is one of the many theories in helping to choose the sex of your child naturally, ok I agree it is one of the better ones. I just thought your first post was a little deceiving in my book but hey that's only my opinion.
The following methods are the more current theories regarding gender selection while trying to conceive.
The Shettles MethodThe Shettles, by Dr. Landrum Shettles and David Rorvik, authors of How to choose the sex of your baby, is the method most used and most effective. According to this method Y-chromosomes (for boys) move faster but don't last as long as X-chromosomes (for girls), Dr Shettles says it makes sense to have sex as close as possible to ovulation if a boy is what you want. If you try to conceive two to four days before you ovulate, you'll most likely have a girl.
The Whelan MethodElizabeth Whelan, Sc.D., author of Boy or Girl?, doesn't agree with the Shettles method and suggests the opposite. Whelan says if you want a boy, have intercourse four to six days before your basal body temperature goes up.
The Ericsson Method In 1975, Ronald J. Ericsson, Ph.D. began clinical studies to determine whether such enriched sperm samples would result in offspring of a desired gender. Today the Ericsson method is used in approximately half of the centers in the US.
Dr Ericsson devised methods by which X and Y sperm can be separated through filtering processes. This sperm sample is used for insemination when ovulation is anticipated. The enriched sperm sample is then available to fertilize the egg.
The Billings MethodA daily record of observations made at the vulva is essential for the Billings Ovulation Method. The recording is made in the evening of the most fertile characteristics noticed throughout the day. The first record, which is begun immediately, is usually of 2 - 4 weeks duration and is made without any genital contact so that the observations will not be confused by any secretions due to intercourse or contact. Your chart provides information for your husband as well, and it helps open the door for communication and decisions during these times.
Sexual Position:Shettles suggests that if you are trying to conceive a boy, deep
penetration from your partner, preferably with the "doggy style"
position, will deposit the sperm closer to the cervix giving the more
aggressive and quicker moving "boy" sperm a head start to
fertilizating the egg first.
Sex and Orgasms:When trying to conceive a boy, Shettles suggests that orgasms during
sex are a good thing as the body produces substances after orgasm that
makes the vaginal environment more alkaline, which favors the "boy"
sperm.
The contractions which accompany an orgasm help move the sperm up and
into the cervix, giving the "boy" sperm an extra chance at being
available when your egg is available for fertilization.
Considerations for the Men:Have your partner wear boxers. Wearing tight fitting underwear
increases the heat levels around the testes and can, in turn, lower
the sperm count. Wearing loose fitting underwear helps keep the testes
cooler.
Have your partner drink a caffeinated beverage right before sex. This
makes the Y-Sperm more active."
My wife and i did none of the above (knowingly) and our first baby (Boy) will be in my arms in 11 weeks
(BTGOG)

Good luck,