{{Short description|Russian chess composer}} {{Use dmy dates|date=October 2025}} '''Leonid Yarosh ('''complete name '''Leonid Vladimirovič Jaroš)''' (born 1957) is a Russian chess composer.
== Biography == {{Infobox person | name = Leonid Vladimirovich Yarosh | other_names =<ref>sometimes reported as Jarosch or Yarosh</ref> | birth_place = Horycja, Chernihiv Oblast, Ukraine | birth_date = 1957 | death_place = | era = 20th–21st century | occupation = Chess composer }} Leonid Yarosh was born in the village of Horycja in Ukraine. As a young man, he moved to Russia, settling in Kazan, where he graduated from the State Institute of Physical Culture. He initially pursued a career as a football coach.<ref>{{Cite web |title=Do you know the Babson task? – Chess Forums |url=https://www.chess.com/forum/view/general/do-you-know-the-babson-task |access-date=16 September 2025 |website=Chess.com |language=en-US}}</ref>
He is best known for composing the first complete chess problem featuring the Babson task in 1983:<ref>{{Cite web |date=1 December 2018 |title=The perfect Babson |url=https://en.chessbase.com/post/the-perfect-babson |access-date=16 September 2025 |website=Chess News |language=en}}</ref><ref>{{Cite web |date=23 May 2023 |title=The Everest of chess problems |url=https://en.chessbase.com/post/the-everest-of-chess-problems |access-date=16 September 2025 |website=Chess News |language=en}}</ref><ref>{{Cite web |title=De man die de Babson Task maakte |url=https://timkr.home.xs4all.nl/admag/kazan.htm |access-date=16 September 2025 |website=timkr.home.xs4all.nl}}</ref> a four-move checkmate problem with multiple promotions to four different pieces. In such a problem, White can achieve mate by promoting to the same piece chosen by Black for promotion; any other promotion fails to deliver checkmate in the prescribed number of moves. Unlike conditional or heterodox chess, White is not forced to replicate Black's promotion – success comes naturally through the Babson theme.
{{Chess diagram | floatleft | '''Leonid Yarosh'''<br />''Šachmaty v SSSR'', 1983<br />1st Prize |bl|qd| |bl| |kl| | | | | |pl|pd|nl| | |pl| | | |pl|pd| | |pl| |pd| | |pl| | | | |pl|kd| |bd| |rl | |pd| | | | | | |pd|nl| |pl| |pl| | |ql|rl| | | | | | |67= <div align="center">White to move and mate in 4<br />with the Babson theme</div> }}
Solution:
'''1. a7!'''
If '''1... axb1=Q 2. axb8=Q Qxb2''' (or 2... Qe4 3. Qxf4 Qxf4 4. Rxf4#) '''3. Qxb3 Qc3 4. Qxc3#''' If '''1... axb1=R 2. axb8=R Rxb2 3. Rxb3 Rxc4 4. Qa4#'''
If '''1... axb1=B 2. axb8=B Be4 3. Bxf4 Bxa8 4. Be3#'''
If '''1... axb1=N 2. axb8=N Nxd2 3. Nc1 Ne4 4. Nc6#''' {{clear}} Afterward, both Yarosh and other composers created additional problems incorporating the complete Babson theme.<ref>{{Cite web |title=Chess Guide > Babson Task |url=https://www.museum.am/chess/com_chessguide/babson_task.html |access-date=16 September 2025 |website=www.museum.am}}</ref>
Yarosh was a member of the Russian team that won the World Chess Composition Team Championships in 1992 and 2004. He also won the Soviet Individual Composition Championship in 1992.
== References == <references />
== External links == * Tim Krabbé article with extensive analysis of Yarosh's problem [https://www.xs4all.nl/~timkr/chess/babs.html The Babson Task] * Photo of Leonid Yarosh (right) with Tim Krabbé in Kazan, 2002 [https://www.xs4all.nl/~timkr/admag/kazan9g.JPG]
{{DEFAULTSORT:Yarosh, Leonid}} Category:Living people Category:1957 births Category:Chess composers Category:Russian chess players