Back in feudal England it was no contest. With rare exceptions, a father had absolute right to custody of his children.

Then the custodial pendulum swung toward Mom. In the mid-1800s courts began following the "tender-years doctrine," which presumes a young child is better off with his or her mother.

But in the last few years, "There's been a major change," says attorney Nelson "Nick" Oneglia.

"The maternal-preference rule has been going by the boards in state after state. In 1978, courts in Maryland (and the District) said men and women would have equal chance for custody under the law."

Along with this move toward "equal-custody opportunity" has come a strong trend toward "shared-divorced parenting," adds Emily M. Brown, director of Arlington's Divorce and Marital Stress Clinic.

"Custody," asserts the psychiatric social worker, "no longer has to be a win-lose proposition. There's an acknowledgment that children need both parents. Fathers seem to have much more interest in custody, and mothers seem more willing to share."

Parents today have several custody options -- and a wide variety of arrangements -- from which to chose, say Oneglia and Brown, who will lead a workshop next week on "Custody: What's Best for the Child and Parent" at The Psychiatric Institute.

From traditional sole custody to the recently-created joint custody, the goal is to find an arrangement that fits "the child's best interests."

"But that's not always easy to determine," admits Oneglia, who practices in Maryland and the District. "It sometimes gets lost in the shuffle of emotions surrounding a divorce."

The best custody arrangements, he says, are those negotiated by both parties as part of the separation and property-settlement agreement. "That way everyone at least has some part in controlling their own destiny.

"When they can't reach an agreement . . . and it goes to court (where some contend judges are still known to rule arbitrarily), you're letting someone who sees both people, and possibly the child, for one, two, or maybe five days, make a lifetime decision.

"And in the Washington area, it's almost 100 percent certain the court is going to award custody to one parent, with visitation for the other. With settlement you have much broader options."

Adds Brown, "While studies show a child's self-concept is unrelated to the type of custody, their self-concept is significantly lower in families where parents maintain high-conflict post-divorce."

There is no "best type of custody," agree Oneglia and Brown, both of whom are custodial parents. Oneglia is remarried to an attorney who also has custody of children form her first marriage.

"I advise people to at least look at each of the options available," says Brown. "You probably won't get what you consider ideal -- but neither will your ex-spouse. I think that both parents -- and the children -- can 'win' if they work out something to fit all their needs."

Here is their outline of major custody options:

Joint custody -- Involves sharing both decision-making and physical time. Although it is "ill-defined in most states," notes Oneglia, the commonly accepted meaning is "that the parents make joint decisions about the major aspects of a child's life -- health, education, religion.

"They also share the amount of time the child is physically with them. It can be a 50-50 split, where the kids are with her Sunday through Wednesday and with him Thursday through Saturday. But it doesn't have to be.It can be just an "every-other weekend" arrangement -- whatever they decide."

An advantage of joint custody, says Oneglia, is that "it's a way of articulating the parents' genuine interest in the child, and a way of letting the child know both parents still have a stake in his or her life."

"For successful joint custody," says Brown, "parents should live close to each other and must be able to communicate. They've got to be mature enough to look beyond the pain and anger and cooperate about the needs of the child.

"I know one joint-custody case where the kids are with the father at night because the mother works nights and with the mother during the day when the father works. It seems to be ideal.

"The children need doubles of some things -- like toothbrushes and pajamas, but they can tote special toys and schoolbooks back and forth."

Despite joint custody's "trendiness," and California's recent law that makes it the first choice of the state courts, both Oneglia and Brown warn that it's "not a panacea" and isn't for everyone.

"Particularly," says Brown, "It's not for people who got divorced because they can't see eye-to-eye on child rearing."

Solo-custody -- Gives one parent full custodial powers and the other parent visitation rights, still the norm in custodial awards in this country. Sole custody is particularly appropriate when parents live in different cities, or if one parent's work schedule involves great deal of travel and overtime.

Mothers are still more apt to have sole custody. "Nine out of 10 children who live with a divorced parent live with their mother," says Census Bureau senior demographer Paul C. Glick.

"Although there is some evidence within the last few years that more children are going with their fathers," he says, "the changes aren't big enough yet to be statistically significant."

"The usual sole-custody visitation schedule," says Oneglia, "is every other weekend, every other holiday, shared Christmas vacations and two weeks to a month in the summer. But this can be broadened or lightened."

"A good visitation agreement should not be too rigid or too flexible," adds Brown. "A too-rigid schedule is usually for the benefit of parents, not the children, stemming from the adults need to get their share and not be taken.'

"If the child has something special to do, like a class picnic on a Saturday when visitation is scheduled, the parents should be able to work something out -- like changing visitation to the next Saturday.

"But it shouldn't be too flexible and allow visitation 'anytime the parent wants to see the kids.' It's better to add 'anytime it's reasonable with 24 hours notice.' There's got to be some structure so everyone knows where they stand."

Split custody -- Divides the siblings, giving custody of one or more of the children to one parent and custody of the remaining children to the other parent.

"It's a very complex, untraditional arrangement," notes Brown."You try to plan time for each child to have alone with each parent, plus time for all the children to be together."

Both Brown and Oneglia express reservations about split custody.

"Siblings need to lean on each other," says Oneglia. "Especially when going through the divorce experience. But sometimes, especially when the children are old, it might be the right choice."

In some cases the boys go with the father and the girls with the mother, says Brown, or the children and parent "with similar interests and the strongest relational ties stay together.

"In one family with four boys, two went with each parent. They weren't the two closest in age, but the two who played together most. The parents live a couple of miles apart, and it's worked out very well."