Certain naming traditions were generally applied in the 17th, 18th and 19th centuries. The problem fpr genealogists is knowing where your ancestor came in his or her family: was he the oldest son? Was she the middle daughter? Were there children who had died before your ancestor was born? Here's the basic pattern:
Any additional children continue the pattern, following the order of father's and mother's brothers and sisters.
One other common practice was to name a child after a child who had died within the family.