John Gill Commentary 2 Kings 16:2

"Twenty years old was Ahaz when he began to reign; and he reigned sixteen years in Jerusalem: and he did not that which was right in the eyes of Jehovah his God, like David his father." — 2 Kings 16:2 (ASV)

Twenty years old was Ahaz when he began to reign, and reigned
sixteen years in Jerusalem
The same number of years his father did:

and did not that which was right in the sight of the Lord God, like
David his father ;
his more remote progenitor, nor even like his more immediate father, from whom he received such good instructions, and of whom he had so good an example; but grace is neither propagated by blood, nor obtained through the force of education.