It is a misconception in today's legal system that mothers stand a better chance of getting custody of their children in a custody battle. The default that many courts use is for both parents to get as much time with their children as possible, and that frequently translates to joint custody and shared parenting time.
So, why does it seem that after a divorce or breakup, mothers may be the ones who have their children most of the time?
If a father decides to pursue his rights to be with his children to the fullest extent possible, he is virtually guaranteed to get shared parenting time (a big change from decades ago). Cases involving domestic violence or abuse may pose exceptions, of course.
Judges, counselors, teachers and many other parties recognize that having two parents involved in a child's life outweighs the child having to change homes every week or month. However, fathers do not always pursue shared parenting time. This can happen for several reasons, including the mothers being possessive, not realizing the benefit of the fathers to their children and the fathers giving in to spare the children a battle. It could also be that the family falls back on a dynamic set during the marriage in which the mother does household and child care tasks while the father brings money home and sees the children less.
In some situations, the father does simply prefer not to have the kids with him as much.
What seems like a choice may not actually be
Sometimes, what seems like a choice is really a father following patterns that were set long ago. For example, if your wife has always criticized your way of changing the children's diapers, how you play with the kids and how you feed them, you may truly believe that you are an inferior parent. Chances are that you are not. You just do things differently. In any case, you may think that for the kids' best interest, you have no choice but to let their mother have them most of the time.
You may be reluctant to challenge your children's mother and make waves, but in the long term, your children will be better off with both of you involved in their lives.