FamilyTreeDNA Learning Center – Do all FTDNATiP™ calculations offer the ability to add genealogical data? Why don’t you always show it?

Do all FTDNATiP™ calculations offer the ability to add genealogical data? Why don’t you always show it?

When using the FTDNATiP™ calculator in myFTDNA, the box in which to enter the number of generations appears only when you are not comparing a perfect match, i.e., when there are mutations between the two individuals. This option is not offered to perfect matches. This is because statistically it does not matter. When it is a perfect match, you will get the same percentages moved back by that number of generations.