al-Adli (800-870) was considered one of the strongest chess (shatranj) players (aliyat) of the 9th century. He was patronized by several caliphs in the Arab world (al-Wathiq who came in power in 842 and al-Mutawakkil who came in power in 847).
He was at the height of his fame around 840 A.D. He was defeated in a match around 848 by ar-Razi in front of Caliph al-Mutawakkil of Baghdad who reigned from 847 until he was murdered by Turks in 861.
al-Adli wrote a book on chess (Kitab ash-shatranj - Book of Shatranj) and a book on nard (Kitab an-nard). His books have long been lost, but some of his problems, endgames, and opening systems have survived. His book contained information on the older game of Chaturanga [Sanskrit], the earlier Indian form of chess.
His name indicates that he came from some part of the eastern Roman Empire, possibly Turkey.
al-Adli was the first person to classify chessplayers. He recognized five classes of players. The highest contained the aliyat or grandees. The second class was called the mutaqaribat or proximes. There were three other classes.
al-Adli was the first to categorize openings into positions called tabiya (plural: tabiyat). Some of the opening names were: the goat-peg, Pharoaoh's stones, the old women, the wing or flank opening, the torrent, the sheikh's opening, the strongly built opening, the sword, the slave's banner, the army opening, and the shoulder.
al-Adli was the first to compile chess problems, called mansubat. He divided his collection into won endings, drawn endings, and undecided games.
al-Adli also showed how to use the chessboard as a kind of abacus for purposes of calculation. The calculation was to be carried out by the help of small stones that were heaped up on the square as necessary. This is a parallel use of the chessboard to that which gave a name to the Exchequer in Norman England.
al Adli may have been the first to use coordinates to record positiosn and moves in chess. He may have also been the first to discover the knights tour. His book contained diagrams which represent a knight's tour on a chessboard.
al-Adli described a variation of chess played with dice. This is the earliest recored instance of the use of dice to determine the moves of a form of chess.
Some of the older legends on the invention of chess comes from al-Adli.
In the first legend, an Indian monarch named Hashran appeals to an Indian sage, Qaflan, to devise a game that would symbolize man'd dependence upon destiny and fate, and depict the way in which these forces work by means of man's environment. The philosopher invented the game of nard, played with dice. Hashran was delighted with the game and introduced it in India, where it became extremely popular. At a later date there arose a king named Balhait who was advised by a Brahman that nard was contrary to his religion. The king accordingly planned to replace nard by a new game, that should demonstrate the value of prudence, diligence, thrift, and knowledge. His Brahman friend undertook the task, and invented chess, explaining its name of shatranj by the Persian hashat-ranj, in which hashat means eight and ranj means side. It was made on the model of war, because war is the most effective school for teaching the value of administration, decision, prudence, caution, arrangement, strategy, circumspection, vigor, force, endurance, and bravery. Balhait was charmed with the game, and did his best to induce his subjects to adopt it in the place of nard.
In the second legend, the game is invented to assist in the military education of a young prince who was incompetent to lead his armies in war owing to his want of experience. Chess is alleged to have given the necessary training in tactics to convert him into an efficient commander.
In the third legend, chess is invented for a king named Shahram by the sage Sassa of Dahir.
al Adli composed an interesting chess problem that can still be played today. For White, place the King on g8, Rooks on e1 and g1, Knight on g3, and Pawn on f4. For Black, place the King on f6, Rooks on d7 and h7, Knight on g6, and Pawn on f5. Now White to move and mate in 3 moves. 1.Nh5+ Rxh5 2.Rxg6 Kxg6 3.Re6 mate.