Khosrow and ridag, and Wizārišn ī čhatrang ("Treatise on Chess"), also known as the Chatrang Nama ("Book of Chess"), all mention chatrang. In Kār-nāmak it is said that Ardashīr "with the help of the gods became more victorious and experienced than all others in polo, horsemanship, chess, backgammon, and other arts," and in the small treatise on Khosrow and ridag, the latter declares that he is superior to his comrades in chess, backgammon, and hašt pāy. Bozorgmehr, the author of Wizārišn ī čhatrang, describes how the game of chess was sent as a test to Khosrow I (r. 531-79) by the "king of the Hindus Dēvsarm" with the envoy Takhtarītūs and how the test was answered by the vizier Bozorgmehr, who in his turn invented the game Backgammon as a test for the Hindus. These three Middle Persian sources do not give any certain indication of the date when chess was introduced into Persia. The mentions of chess in Kar-Namag i Ardashir i Pabagan and Khosrow and ridag are simply conventional and may easily represent late Sasanian or even post-Sasanian redactions. According to Touraj Daryaee, Kar-Namag i Ardashir i Pabagan is from 6th century. Wizārišn ī čhatrang was written in the 6th century. Early Arabic literature During the Islamic Golden Age, many works on shatranj were written, recording for the first time the analysis of opening moves, game problems, the knight's tour, and many more subjects common in modern chess books. Many of these manuscripts are missing, but their content is known due to compilation work done by the later authors. The earliest listing of works on chess is in the Fihrist, a general bibliography produced in 377 AH (988 AD) by Ibn al-Nadim. It includes an entire section on the topic of chess, listing: Al-Adli's Kitab ash-shatranj ('Book of Chess') Ar-Razi's Latif fi 'sh-shatranj ('Fun with Chess') As-Suli's Kitab ash-shatranj (two volumes) Al-Lajlaj's Kitab mansubat ash-shatranj ('Book: Strategies of Chess') B. Aluqlidisi's Kitab majmu' fi mansubat ash-shatranj ('Book: Intent of Strategies of Chess') There is a passage referring to chess in a work said to be by al-Hasan al-Basri, a philosopher from Basra who died in 728 AD. The attribution of authorship is dubious, however. Player classification Al-Adli as well as As-Suli introduced classifications of players by their playing strength. Both of them specify five classes of players: Aliyat (or aliya), grandees Mutaqaribat, proximes – players who could win