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.
Jon Snow. Jon Snow is the bastard son of Eddard Stark, Lord of Winterfell. He has five half-siblings: Robb, Sansa, Arya, Bran, and Rickon Stark. Unaware of the identity of his mother, Jon was raised at Winterfell. At the age of fourteen, he joins the Night's Watch, where he earns the nickname Lord Snow. Jon is one of the major POV characters in A Song of Ice and Fire.