Cost-benefit analysis is a weighing-scale approach to making business decisions: all the pluses (the benefits) are put on one side of the balance and all the minuses (the costs) are put on the other. Whichever weighs the heavier wins.
However, since the story constantly points out Jon's conflict with his illegitimacy and Ned's strict code of honor, many fans have come up with a theory that actually explains who they think Jon's parents really are. Fans know the theory as R+L=J.. R+L=J would refer to Jon Snow (J) being the child of Rhaegar Targaryen (R) and Ned Stark's sister, Lyanna Stark (L) rather than Jon being the illegitimate child of Ned.
One of the unresolved issues in A Song of Ice and Fire is the identity of Jon Snow's mother. â. . . .Even his own mother had not had a place for him. The thought of her made him sad. He wondered who she had been, what she had looked like, why his father had left her.