How many generations were there between Abraham to David? Matthew 1:17 says fourteen generations but  Matthew 1:2-6 lists only thirteen.

Abraham(1) was the father of Isaac(2), and Isaac the father of Jacob(3), and Jacob the father of Judah and his brothers(4), and Judah the father of Perez and Zerah by Tamar(5), and Perez the father of Hezron(6), and Hezron the father of Ram(7), and Ram the father of Amminadab(8), and Amminadab the father of Nahshon(9), and Nahshon the father of Salmon(10), and Salmon the father of Boaz by Rahab(11), and Boaz the father of Obed by Ruth(12), and Obed the father of Jesse(13), and Jesse the father of David the king(14). (Matt. 1:2-6)

The first series of genealogies is different from the two that follow it in that this series includes the start of the whole collection of names. There are fourteen names listed in this portion including Abraham’s. Since Abraham was the first of the names listed and is obviously not listed in a previous list such as David is in Matthew 1:6 and Jechoniah in Matthew 1:11-12, his is to be considered a genealogy in and of itself, making the total number in the bloodline fourteen.