Thiele showed that for the reign of Jehoram, Judah adopted Israel's non-accession method of counting the years of reign, meaning that the first partial year of the king's reign was counted as his first full year, in contrast to the "accession" method previously in use, whereby the first partial year was counted as year "zero", and "year one" was assigned to the first full year of reign. Thiele attributed this change to the rapprochement between Judah and Israel, whereby Jehoshaphat, Jehoram's father, united with Ahab at the battle of Ramoth-Gilead, and chose a daughter for his son from the house of Ahab (, ). This convention was followed in Judah for the next three monarchs: Ahaziah, Athaliah, and Jehoash, returning to Judah's original accession reckoning in the time of Amaziah. These changes can be inferred by comparison of the textual data in the Bible; however, the biblical texts do not explicitly state whether the reckoning was by accession or non-accession counting, nor do they indicate explicitly when a change was made in the method. Thiele's reckoning has been criticized as arbitrary in its assignment of accession and non-accession dating systems. The official records of Tiglath-Pileser III show that he switched (arbitrarily) to non-accession reckoning for his reign, in contrast with the accession method used for previous kings of Assyria. Tiglath-Pileser left no record for modern historians to indicate which dating method he used, nor whether he was switching from the method used by his predecessors; this is instead determined by comparison of the relevant texts by Assyriologists, the same as Thiele did for the regnal data of Judah and Israel.