Editing Abu Bakr bin Yahya al-Suli (section)

==Life==
Abū Bakr al-Ṣūlī was born into an illustrious family of Turkic origin, his great-grandfather was the [[Turkic people|Turkic]] prince [[Sul-takin]] and his uncle was the poet Ibrahim ibn al-'Abbas as-Suli.<ref>{{cite book|last1=Osaulai|first1=Muohammad Ibn Yaohyaa|title=The Life and Times of Abu Tammam|date=2015|publisher=Library of Arabic Literature|isbn=9780814760406}}</ref>
[[Al-Marzubānī]], a principal pupil of al-Ṣūlī, who admired him and copied him in the art of compilation, borrowed much of al-Ṣūlī's material for his ''Kitāb al-Muwashshaḥ''. [[Abu al-Faraj al-Isfahani|Abū al-Faraj al-Iṣbahānī]] made extensive use of his material in his ''[[Kitab al-Aghani|Kitāb al-Aghānī]]''.{{sfn|Ṣūlī (al-)|1936|p=10}}                          
On Caliph al-Rāḍī's death in 940, al-Ṣūlī fell into disfavour with the new ruler due to his [[Shi'a]] sympathies and he died hiding at [[Basra|al-Baṣrah]],{{sfn|Nadīm (al-)|1970|p=329}}  for having quoted a passage about ‘Alī, which caused a public scandal.{{sfn|Nadīm (al-)|1970|p=330}}

===Chess{{sfn|Nadīm (al-)|1970|p=341}}{{sfn|Nadīm (al-)|1872|p=566}}===
Al-Ṣūlī was among a group of tenth-century chess players who wrote books about the game of [[Shatranj|shaṭranj]], i.e. "chess".{{refn|group=n|The word shiṭranj, often written shaṭranj, is a corrupted form of the Indian word chaturanga, which was originally a military term. The word "chess" derives from shāh or shaykh.}}{{sfn|Nadīm (al-)|1970|p=341}}

Al-Ṣūlī's books were:
*''Kitāb al-Shiṭranj al-Nisḥa al-Awala'' ({{lang|ar|كتاب الشطرنج النسخة الاولة}}) ‘Chess, the first manuscript’;
*''Kitāb al-Shiṭranj al-Nisḥa ath-Thānīa'' ({{lang|ar|كتاب الشطرنج النسخة الثانية}}) Chess, the second manuscript; Book on [[chess strategy]], common [[chess opening]]s, standard problems in middle game, annotated end games and the first known description of the [[knight's tour]] problem.
Sometime between 902 and 908, al-Ṣūlī played and beat the reigning shaṭranj champion, al-Mawardī, at the court of Caliph al-Muktafī, and the [[Caliph of Baghdad]]. When al-Muktafī died, al-Ṣūlī retained the favour of the succeeding rulers, Caliph al-Muqtadir and Caliph al-Radi.

His biographer [[Ibn Khallikan]], (d. 1282), relates that even in his lifetime the phrase "to play like al-Ṣūlī" was to show great skill at shaṭranj. His [[Chess endgame|endgame]] strategies are still studied. Contemporary biographers mention his skill in [[blindfold chess]]. Al-Ṣūlī also taught shaṭranj. Many later European writers{{who|date=July 2018}} based their work on modern chess on al-Suli's work.

===Other Chess players/authors in the Group{{sfn|Nadīm (al-)|1970|p=341}}===
*[[Al-Adli ar-Rumi|Al-‘Adlī]] ({{lang|ar|العَدْلى}}) wrote:
{{snd}}''Kitāb al-Shiṭranj'' ({{lang|ar|كتاب الشطرنج}}) ‘Chess’, the first book on chess,{{refn|group=n|Al-Nadīm tells us that al-‘Adlī wrote the first book on the game of chess.{{sfn|Nadīm (al-)|1970|p=342}}}} and;
{{snd}}''[[Al-Nard, wa Isbābha wa-al-La’ab bīha]]'' ({{lang|ar|كتاب النرد واسبابها واللعب بها}}). 'Al-Nard Its Elements and Play'.{{refn|group=n|Al-nardashīr, board games like backgammon or checkers. See "Shaṭrandj," Enc. Islām, IV, 338;  Asiatic Journal and Monthly Register, V (June, 1818), 121.}}
*[[Al-Rāzī]] ({{lang|ar|الرازى}}) was a chess rival of al-‘Adlī and the caliph [[Al-Mutawakkil]] attended their matches. He wrote:
{{snd}}''Kitāb latīf fī al- Shiṭranj'' ({{lang|ar|كتاب لطيف في الشطرنج}}) ‘A Delightful Book about Chess.’
*Abū al-Faraj Muḥammad ibn ‘Ubayd Allāh [[al-Lajlaj|al-Lajlāj]] ("the stammerer") ({{lang|ar|ابو الفرج محمد بن عبيد الله اللَجْلاج}}), whom Isḥāq al-Nadīm had met, was his best known pupil. He excelled at chess at the [[Buyid dynasty|Būyid]] court of king [['Adud al-Dawla|‘Aḍud al-Dawlah]] in [[Shiraz|Shīrāz]], where he died sometime after 970/71 [360 AH]. He wrote:
{{snd}}''Manṣūbāt al-Shiṭranj'' ({{lang|ar|منصوبات الشطرنج}}) ‘The Stratagems of Chess.’
*Ibn al-Uqlīdasī Abū Isḥāq Ibrāhīm ibn Muḥammad ibn Ṣāliḥ, one of the most skilful chess players, who wrote ''A Collection of the Stratagems of Chess''.{{sfn|Nadīm (al-)|1970|p=342}}

===Al-Suli's Diamond===
{{chaturanga diagram
| tright
|
|  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |
|  |  |  |  |  |  |  |
|  |  |  |kd|  |  |  |
|  |  |  |  |  |  |  |
|  |kl|ql|  |  |  |  |
|  |  |  |  |  |  |  |
|qd|  |  |  |  |  |  |

| White to move, White wins}}

Al-Ṣūlī's shaṭranj problem, called "Al-Ṣūlī's Diamond", went unsolved for over a thousand years.<ref>{{citation|last=Shenk|first=David|title=The Immortal Game: A History of Chess}}</ref>
As this is shaṭranj, the "queen" (counsellor) is a very weak piece, able to move only a single square diagonally. It is possible to win in shaṭranj by capturing all pieces except the king, unless the opponent is able to do the same on the next move.

{{blockquote|This ancient position is so difficult that there is no one in the world who would be able to solve it, except those I have taught to do so. I doubt whether anyone did this before me. This was said by al-Suli.|12th-century manuscript from the library of Sultan [[Abdul Hamid]]<ref name="Damsky"/>}}

[[David Vincent Hooper|David Hooper]] and [[Ken Whyld]] studied this problem in the mid-1980s but were unable to crack it. It was finally solved by Russian [[Grandmaster (chess)|Grandmaster]] [[Yuri Averbakh]].<ref name="Damsky">{{citation|last=Damsky|first=Yakov|year=2005|title=The Book of Chess Records|publisher=Batsford|isbn=0-7134-8946-4|pages=[https://archive.org/details/batsfordbookofch0000dams/page/166 166–167]|url=https://archive.org/details/batsfordbookofch0000dams/page/166}}</ref><ref>{{citation
| last=Ree|first=Hans|author-link=Hans Ree|year=2000|title=The Human Comedy of Chess
| publisher=Access Publishers Network}}</ref> The solution, starting with 1. Kb4, is given in Hans Ree's "The Human Comedy of Chess", and on the web.<ref>{{cite web | title = Exeter Chess Club blog | author = DrDave | year = 2013 | url = http://exeterchessclub.org.uk/content/sulis-diamond}}</ref><ref>{{cite web | title = John's Chess Playground | author = John Tromp | year = 2013 | url = https://tromp.github.io/chess/chess.html}}</ref>