A recent case decided in the Appellate Division Second Department makes clear that in custody litigation, the court can award sole custody to one parent, while providing for decision making in specific areas of the child's life, to the other. See Jacobs v. Young 2013 NY Slip Op 04607.
For example, if the non-custodial parent can prove to the court that she or he has had a far more active interest in the child's education, has worked consistently with the child with homework and special assignments, and has always attended parent teacher night, this might be a proper basis to award the father decision making with regard to education, while directing that the mother shall have sole custodial custody. We also learn from this case that the judge hearing the case has wide latitude and discretion to consider most any evidence bearing upon the best interests of the child. Religion is another area that can be delegated to the non-custodial parent, especially where the other does not follow their own faith.
The bottom line is that the court can look at the totality of the circumstances and consider any fact or argument if the judge feels it would be in the children's best interest to do so. This is not a very objective standard and it stands in the way of accurately predicting the ultimate determination to be made regarding the division of decision making as to the child's health, education, religion, or general welfare. Moreover, depending upon the background and the predilections of the court assigned to hear the case, disparate decision can be made. Law and the determinations to be made by the court is not an exact science. It is really an art form that can vary greatly even when the facts of the case seem to mirror a reported case that considered the same issues.
Armed with this knowledge, your attorney should be trying your case with the view of creating a record that can be reviewed by an appellate court in the event the decision is unfavorable and the case must be appealed. It is to be remembered that the appellate court cannot consider any facts or arguments that was not made before the trial court. That it is why you should be certain to reveal all facts to your lawyer that may be relevant to your request for custody or visitation.
The division of decision making makes it far easier for the court to award joint custody, which they normally will not direct between warring parents.