I tried hard to stay away from this. One billion sperm racing down the chute and the leader pulls up and lets the potential boy thru while saying "we have already been to the trough" Hard and fast the sperm has no prior memory etc This is a straight out 50/50 possible outcome.

At this point other factors arise. Most of these are statitical analysis of past results which have no direct bearing on this event. However people read their own interpretations from these results. The ratio of boys to girls is 50/50 and there is one girl already hence there is a 100% chance that this is a boy. Boy/girl and Girl/Girl is still only 50/50 because we are only dealing with the possible outcome so the factual portion (we already have a girl) is deleted leaving whether this one will be a boy or girl. Other factors may sutblely alter the odds ie a history of girls on both sides of the family,This area produces on average 75% girls or this is Amazonia and boys do not survive birth.
The only way to change it from 50/50 is to show that there is a greater proportion of one sex in the sperm count because nobody is going to say thatone sex swims faster than the other.

this is my only comment as i refuse to allow the quality of the forum to deteriorate.

Besides that I wish all a good day