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Created page with "'''Home * Engines * Senpai''' border|right|thumb|[[:Category:Katsushika Hokusai|Katsushika Hokusai, The Great Wave off..."
'''[[Main Page|Home]] * [[Engines]] * Senpai'''
[[FILE:Great Wave off Kanagawa2.jpg|border|right|thumb|[[:Category:Katsushika Hokusai|Katsushika Hokusai]], The Great Wave off Kanagawa <ref>[https://en.wikipedia.org/wiki/The_Great_Wave_off_Kanagawa The Great Wave off Kanagawa], [[Arts#Hokusai|Katsushika Hokusai]], c. 1829–32, the first print in Hokusai's series [https://en.wikipedia.org/wiki/Thirty-six_Views_of_Mount_Fuji Thirty-six Views of Mount Fuji], current location: [https://en.wikipedia.org/wiki/Library_of_Congress Library of Congress], see [https://en.wikipedia.org/wiki/Culture_of_Japan Culture of Japan]</ref>
]]
'''Senpai''', (Japanese: 先輩)<br/>
an [[UCI]] compliant [[Open Source Engines|open source chess engine]] by [[Fabien Letouzey]], written from scratch in [[Cpp#11|C++11]] and distributed under the [[Free Software Foundation#GPL|GNU General Public License version 3]]. Senpai 1.0 was precisely published ten years after the release of [[Fruit|Fruit 1.0]] on March 17, 2014 <ref>[http://www.talkchess.com/forum/viewtopic.php?t=51637 Senpai 1.0 (new engine)] by [[Fabien Letouzey]], [[CCC]], March 17, 2014</ref> . It comes with one source file, senpai_10.cpp, structured by namespaces, further with [https://en.wikipedia.org/wiki/Executable executables] for various platforms and operating systems, such as [[Linux]], [[Mac OS]], [[Windows]] and [[Android]] <ref>[http://www.chessprogramming.net/senpai/ Senpai Chess Engine - Computer Chess Programming] hosted by [[Steve Maughan]]</ref>. Senpai '''2.0''' released in November 2017 was a complete rewrite with a consistent codebase for multiple games such as [[Draughts]], [[Chess960]], [[Shogi]], and [[Othello]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=65680 Senpai 2.0] by [[Fabien Letouzey]], [[CCC]], November 10, 2017</ref>.
=Description=
==Board Representation==
Senpai is a [[Bitboards|bitboard]] engine and [[Square Mapping Considerations#LittleEndianFileRankMapping|maps]] consecutive bits to squares along a [[Files|file]] (a1,a2,...,a8,b1,...h8). With the option to implement [[Magic Bitboards|magic bitboards]] later, Senpai so far uses the [[Blockers and Beyond]] loop approach to determine attack-sets for all pieces except pawns, while Senpai '''2.0''' features [[BMI2#PEXTBitboards|PEXT bitboards]] for [[BMI2]] platforms. [[BitScan]] aka [[BitScan#TrailingZeroCount|trailing zero count]], and [[Population Count|population count]] use [https://en.wikipedia.org/wiki/GNU_Compiler_Collection GCC] builtins <ref>__builtin_ctzll,__ builtin_popcountll, [http://gcc.gnu.org/onlinedocs/gcc-3.4.3/gcc/Other-Builtins.html Other Builtins - Using the GNU Compiler Collection (GCC)]</ref> if available for the target architecture, and otherwise rely on [[BitScan#DeBruijnMultiplation|De Bruijn multiplication]] and [[Population Count#SWARPopcount|SWAR-popcount]]. In Senpai '''2.0''' the [[Copy-Make|copy/make]] approach is used, customary in games with fewer [[Pieces|piece types]] than chess.
[[FILE:lefr.JPG|none|border|text-bottom|326px|link=Bibob]]
Senpai's [[Square Mapping Considerations#LittleEndianFileRankMapping|Little-Endian File-Rank Mapping]] <ref>[[Bibob]] image</ref>
==Search==
Senpai applies a [[Parallel Search|parallel search]] with one master and a pool of helper [[Thread|threads]], following the [[Young Brothers Wait Concept]]. The serial search is [[Principal Variation Search|PVS]] [[Alpha-Beta|alpha-beta]] with [[Transposition Table|transposition table]] inside an [[Iterative Deepening|iterative deepening]] framework with [[Aspiration Windows|aspiration windows]]. Beside the obligarory [[Null Move Pruning|Null move pruning]] and [[Late Move Reductions|LMR]], Senpai further uses [[Futility Pruning#MoveCountBasedPruning|late move pruning]] and more aggressive [[Futility Pruning|futility pruning]] the last few plies. Senpai '''2.0''' further applies [[Singular Extensions#RestrictedSE|restricted singular extensions]] and additional [[Reductions|reduction]]/[[Pruning|pruning]] of "losing" moves ([[Static Exchange Evaluation|SEE]]< 0).
==Evaluation==
Compared to Fruit's [[Evaluation|evaluation]], Senpai has a more precise [[Mobility|mobility]] considering safety and [[Center Control|center weights]], and evaluates tactical moves. Senpai '''2.0''' considers a [[Tempo|tempo]] and [[Space|space]], and uses a scoring by [[Automated Tuning#LogisticRegression|logistic regression]].
=Etymology=
Senpai is a Japanese term applied to the mentor system in wide use in [https://en.wikipedia.org/wiki/Culture_of_Japan Japanese culture], roughly equivalent to the Western concept of a [https://en.wikipedia.org/wiki/Mentorship mentorship]. In [https://en.wikipedia.org/wiki/Japanese_martial_arts Japanese martial arts], the term Senpai generally refers to senior level students who hold a [https://en.wikipedia.org/wiki/Black_belt_%28martial_arts%29 black belt] <ref>[https://en.wikipedia.org/wiki/Senpai_and_k%C5%8Dhai Senpai and kōhai - Wikipedia]</ref> . Use in English may carry humorous or affectionate connotations. This is possibly due to (assumed) reference to modern [https://en.wikipedia.org/wiki/Media_of_Japan Japanese media], or possibly a [https://en.wikipedia.org/wiki/Accidental_gap lexical gap] <ref>[http://en.wiktionary.org/wiki/senpai senpai - Wiktionary]</ref> .
=See also=
* [[Chess-64]]
* [[Fruit]]
* [[Kōhai]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=60393 Kohai 1.0 Released - a Senpai Derivative] by [[Michael Byrne|Michael B]], [[CCC]], June 06, 2016</ref> <ref>[https://github.com/MichaelB7/Kohai-Chess GitHub - MichaelB7/Kohai-Chess: UCI Chess Engine, a derivative of Senpai 1.0]</ref>
=Forum Posts=
* [http://www.talkchess.com/forum/viewtopic.php?t=51637 Senpai 1.0 (new engine)] by [[Fabien Letouzey]], [[CCC]], March 17, 2014
* [http://www.talkchess.com/forum/viewtopic.php?t=51652 First blitz impressions: Senpai 1.0 et al] by [[Michael Scheidl|Mike Scheidl]], [[CCC]], March 18, 2014
* [http://www.open-chess.org/viewtopic.php?f=5&t=2618 C++11 threads seem to get shafted for cycles] by [[Dann Corbit|User923005]], [[Computer Chess Forums|OpenChess Forum]], March 18, 2014 » [[Cpp|C++]], [[Parallel Search]], [[Thread]]
* [http://www.talkchess.com/forum/viewtopic.php?t=60393 Kohai 1.0 Released - a Senpai Derivative] by [[Michael Byrne|Michael B]], [[CCC]], June 06, 2016
* [http://www.talkchess.com/forum/viewtopic.php?t=65680 Senpai 2.0] by [[Fabien Letouzey]], [[CCC]], November 10, 2017
=External Links=
==Chess engine==
* [http://www.chessprogramming.net/senpai/ Senpai Chess Engine - Computer Chess Programming] hosted by [[Steve Maughan]]
* [http://www.amateurschach.de/main/_senpai.htm Frank's Chess Page, Senpai by Fabian Letouzey] hosted by [[Frank Quisinsky]]
* [http://www.computerchess.org.uk/ccrl/4040/cgi/engine_details.cgi?match_length=30&each_game=1&print=Details&each_game=1&eng=Senpai%202.0%2064-bit%204CPU#Senpai_2_0_64-bit_4CPU Senpai 2.0 64-bit 4CPU] in [[CCRL|CCRL 40/40]]
==Misc==
* [https://en.wikipedia.org/wiki/Senpai_and_k%C5%8Dhai Senpai and kōhai - Wikipedia]
* [http://en.wiktionary.org/wiki/senpai senpai - Wiktionary]
* [http://en.wiktionary.org/wiki/%E5%85%88%E8%BC%A9 先輩 - Wiktionary]
* [https://en.wikipedia.org/wiki/Sensei Sensei - Wikipedia]
* [https://www.ronniescotts.co.uk/performances/view/896-hiromi-the-trio-project-featuring-steve-smith-and-anthony-jackson Hiromi The Trio Project] – [https://en.wikipedia.org/wiki/Another_Mind Dançando no Paraíso], [https://en.wikipedia.org/wiki/YouTube YouTube] Video
: [[:Category:Hiromi Uehara|Hiromi Uehara]], [[:Category:Anthony Jackson|Anthony Jackson]], [https://en.wikipedia.org/wiki/Steve_Smith_(musician) Steve Smith]
: {{#evu:https://www.youtube.com/watch?v=AtSlIG_HKeg|alignment=left|valignment=top}}
=References=
<references />
'''[[Engines|Up one level]]'''
[[Category:UCI]]
[[Category:Open Source]]
[[Category:GPL]]
[[Category:Katsushika Hokusai]]
[[Category:Hiromi Uehara]]
[[Category:Anthony Jackson]]
[[FILE:Great Wave off Kanagawa2.jpg|border|right|thumb|[[:Category:Katsushika Hokusai|Katsushika Hokusai]], The Great Wave off Kanagawa <ref>[https://en.wikipedia.org/wiki/The_Great_Wave_off_Kanagawa The Great Wave off Kanagawa], [[Arts#Hokusai|Katsushika Hokusai]], c. 1829–32, the first print in Hokusai's series [https://en.wikipedia.org/wiki/Thirty-six_Views_of_Mount_Fuji Thirty-six Views of Mount Fuji], current location: [https://en.wikipedia.org/wiki/Library_of_Congress Library of Congress], see [https://en.wikipedia.org/wiki/Culture_of_Japan Culture of Japan]</ref>
]]
'''Senpai''', (Japanese: 先輩)<br/>
an [[UCI]] compliant [[Open Source Engines|open source chess engine]] by [[Fabien Letouzey]], written from scratch in [[Cpp#11|C++11]] and distributed under the [[Free Software Foundation#GPL|GNU General Public License version 3]]. Senpai 1.0 was precisely published ten years after the release of [[Fruit|Fruit 1.0]] on March 17, 2014 <ref>[http://www.talkchess.com/forum/viewtopic.php?t=51637 Senpai 1.0 (new engine)] by [[Fabien Letouzey]], [[CCC]], March 17, 2014</ref> . It comes with one source file, senpai_10.cpp, structured by namespaces, further with [https://en.wikipedia.org/wiki/Executable executables] for various platforms and operating systems, such as [[Linux]], [[Mac OS]], [[Windows]] and [[Android]] <ref>[http://www.chessprogramming.net/senpai/ Senpai Chess Engine - Computer Chess Programming] hosted by [[Steve Maughan]]</ref>. Senpai '''2.0''' released in November 2017 was a complete rewrite with a consistent codebase for multiple games such as [[Draughts]], [[Chess960]], [[Shogi]], and [[Othello]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=65680 Senpai 2.0] by [[Fabien Letouzey]], [[CCC]], November 10, 2017</ref>.
=Description=
==Board Representation==
Senpai is a [[Bitboards|bitboard]] engine and [[Square Mapping Considerations#LittleEndianFileRankMapping|maps]] consecutive bits to squares along a [[Files|file]] (a1,a2,...,a8,b1,...h8). With the option to implement [[Magic Bitboards|magic bitboards]] later, Senpai so far uses the [[Blockers and Beyond]] loop approach to determine attack-sets for all pieces except pawns, while Senpai '''2.0''' features [[BMI2#PEXTBitboards|PEXT bitboards]] for [[BMI2]] platforms. [[BitScan]] aka [[BitScan#TrailingZeroCount|trailing zero count]], and [[Population Count|population count]] use [https://en.wikipedia.org/wiki/GNU_Compiler_Collection GCC] builtins <ref>__builtin_ctzll,__ builtin_popcountll, [http://gcc.gnu.org/onlinedocs/gcc-3.4.3/gcc/Other-Builtins.html Other Builtins - Using the GNU Compiler Collection (GCC)]</ref> if available for the target architecture, and otherwise rely on [[BitScan#DeBruijnMultiplation|De Bruijn multiplication]] and [[Population Count#SWARPopcount|SWAR-popcount]]. In Senpai '''2.0''' the [[Copy-Make|copy/make]] approach is used, customary in games with fewer [[Pieces|piece types]] than chess.
[[FILE:lefr.JPG|none|border|text-bottom|326px|link=Bibob]]
Senpai's [[Square Mapping Considerations#LittleEndianFileRankMapping|Little-Endian File-Rank Mapping]] <ref>[[Bibob]] image</ref>
==Search==
Senpai applies a [[Parallel Search|parallel search]] with one master and a pool of helper [[Thread|threads]], following the [[Young Brothers Wait Concept]]. The serial search is [[Principal Variation Search|PVS]] [[Alpha-Beta|alpha-beta]] with [[Transposition Table|transposition table]] inside an [[Iterative Deepening|iterative deepening]] framework with [[Aspiration Windows|aspiration windows]]. Beside the obligarory [[Null Move Pruning|Null move pruning]] and [[Late Move Reductions|LMR]], Senpai further uses [[Futility Pruning#MoveCountBasedPruning|late move pruning]] and more aggressive [[Futility Pruning|futility pruning]] the last few plies. Senpai '''2.0''' further applies [[Singular Extensions#RestrictedSE|restricted singular extensions]] and additional [[Reductions|reduction]]/[[Pruning|pruning]] of "losing" moves ([[Static Exchange Evaluation|SEE]]< 0).
==Evaluation==
Compared to Fruit's [[Evaluation|evaluation]], Senpai has a more precise [[Mobility|mobility]] considering safety and [[Center Control|center weights]], and evaluates tactical moves. Senpai '''2.0''' considers a [[Tempo|tempo]] and [[Space|space]], and uses a scoring by [[Automated Tuning#LogisticRegression|logistic regression]].
=Etymology=
Senpai is a Japanese term applied to the mentor system in wide use in [https://en.wikipedia.org/wiki/Culture_of_Japan Japanese culture], roughly equivalent to the Western concept of a [https://en.wikipedia.org/wiki/Mentorship mentorship]. In [https://en.wikipedia.org/wiki/Japanese_martial_arts Japanese martial arts], the term Senpai generally refers to senior level students who hold a [https://en.wikipedia.org/wiki/Black_belt_%28martial_arts%29 black belt] <ref>[https://en.wikipedia.org/wiki/Senpai_and_k%C5%8Dhai Senpai and kōhai - Wikipedia]</ref> . Use in English may carry humorous or affectionate connotations. This is possibly due to (assumed) reference to modern [https://en.wikipedia.org/wiki/Media_of_Japan Japanese media], or possibly a [https://en.wikipedia.org/wiki/Accidental_gap lexical gap] <ref>[http://en.wiktionary.org/wiki/senpai senpai - Wiktionary]</ref> .
=See also=
* [[Chess-64]]
* [[Fruit]]
* [[Kōhai]] <ref>[http://www.talkchess.com/forum/viewtopic.php?t=60393 Kohai 1.0 Released - a Senpai Derivative] by [[Michael Byrne|Michael B]], [[CCC]], June 06, 2016</ref> <ref>[https://github.com/MichaelB7/Kohai-Chess GitHub - MichaelB7/Kohai-Chess: UCI Chess Engine, a derivative of Senpai 1.0]</ref>
=Forum Posts=
* [http://www.talkchess.com/forum/viewtopic.php?t=51637 Senpai 1.0 (new engine)] by [[Fabien Letouzey]], [[CCC]], March 17, 2014
* [http://www.talkchess.com/forum/viewtopic.php?t=51652 First blitz impressions: Senpai 1.0 et al] by [[Michael Scheidl|Mike Scheidl]], [[CCC]], March 18, 2014
* [http://www.open-chess.org/viewtopic.php?f=5&t=2618 C++11 threads seem to get shafted for cycles] by [[Dann Corbit|User923005]], [[Computer Chess Forums|OpenChess Forum]], March 18, 2014 » [[Cpp|C++]], [[Parallel Search]], [[Thread]]
* [http://www.talkchess.com/forum/viewtopic.php?t=60393 Kohai 1.0 Released - a Senpai Derivative] by [[Michael Byrne|Michael B]], [[CCC]], June 06, 2016
* [http://www.talkchess.com/forum/viewtopic.php?t=65680 Senpai 2.0] by [[Fabien Letouzey]], [[CCC]], November 10, 2017
=External Links=
==Chess engine==
* [http://www.chessprogramming.net/senpai/ Senpai Chess Engine - Computer Chess Programming] hosted by [[Steve Maughan]]
* [http://www.amateurschach.de/main/_senpai.htm Frank's Chess Page, Senpai by Fabian Letouzey] hosted by [[Frank Quisinsky]]
* [http://www.computerchess.org.uk/ccrl/4040/cgi/engine_details.cgi?match_length=30&each_game=1&print=Details&each_game=1&eng=Senpai%202.0%2064-bit%204CPU#Senpai_2_0_64-bit_4CPU Senpai 2.0 64-bit 4CPU] in [[CCRL|CCRL 40/40]]
==Misc==
* [https://en.wikipedia.org/wiki/Senpai_and_k%C5%8Dhai Senpai and kōhai - Wikipedia]
* [http://en.wiktionary.org/wiki/senpai senpai - Wiktionary]
* [http://en.wiktionary.org/wiki/%E5%85%88%E8%BC%A9 先輩 - Wiktionary]
* [https://en.wikipedia.org/wiki/Sensei Sensei - Wikipedia]
* [https://www.ronniescotts.co.uk/performances/view/896-hiromi-the-trio-project-featuring-steve-smith-and-anthony-jackson Hiromi The Trio Project] – [https://en.wikipedia.org/wiki/Another_Mind Dançando no Paraíso], [https://en.wikipedia.org/wiki/YouTube YouTube] Video
: [[:Category:Hiromi Uehara|Hiromi Uehara]], [[:Category:Anthony Jackson|Anthony Jackson]], [https://en.wikipedia.org/wiki/Steve_Smith_(musician) Steve Smith]
: {{#evu:https://www.youtube.com/watch?v=AtSlIG_HKeg|alignment=left|valignment=top}}
=References=
<references />
'''[[Engines|Up one level]]'''
[[Category:UCI]]
[[Category:Open Source]]
[[Category:GPL]]
[[Category:Katsushika Hokusai]]
[[Category:Hiromi Uehara]]
[[Category:Anthony Jackson]]
