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'''Chinese Chess''', or '''Xiangqi''' 象棋 <ref>[https://groups.google.com/d/msg/rec.games.chinese-chess/gcreEzzU3yQ/HvWOlP7yaYkJ Xiang Qi Is Not The Elephant Game] by Stephen Leary, [[Computer Chess Forums|rec.games.chinese-chess]], November 18, 1994</ref>,<br/>is a chess variant which is very popular in east East Asia, specially especially in China and Vietnam. The Chinese Chess set includes a board and 32 pieces for two players. The board has ten horizontal lines called [[Ranks|ranks]] and nine vertical lines called [[Files|files]]. Pieces are located not in the cells but intersectional points of ranks and files which are 90 in total. In the middle of the board the central seven files are interrupted by a horizontal space called the “River”, which splits the board into two parts. <span id="Palace"></span>Each side of the board has a “Palace” a 3x3 area in the central base. The seven kind of pieces are placed on the intersections and move and capture according to their individual ability and restriction along the lines including the “River banks”. The two sides are usually distinguished by colorcolors, being traditional names are red or black <ref>[[Shi-Jim Yen]], [[Jr-Chang Chen]], [[Tai-Ning Yang]], [[Shun-Chin Hsu]] ('''2004'''). ''[https://www.researchgate.net/publication/220174553_Computer_Chinese_Chess Computer Chinese Chess]''. [[ICGA Journal#27_1|ICGA Journal, Vol. 27, No. 1]], [https://pdfs.semanticscholar.org/223d/ef59c884503f18610bba314034157f55aacd.pdf pdf]</ref> but now they can be called white and black as chess. Sometimes the Xiangqi board could be considered as the presentation of the war between two countries when the standard chess presents for a battle only.

Basically the rules =Pieces=There are similar to chess7 types: King, Advisor, Elephant, Rook, Cannon, Horse, and Pawn. The object of the game is to [[Checkmate|checkmate]] Typically those pieces are made from small, simple wood pieces which some symbols (new way) or [[Stalemate|stalemate]] Chinese characters (is a win as welltraditional way) written on them. As the opponent King aka General. HoweverChinese characters, partly due to pieces on the white side may use different characters than their counterparts on the freedom and power of black side. They are the Rook over other same pieces, and but names on the limited freedom of White side are subtly more noble than those on the King, it is forbidden to Black side <ref>[[Repetitions|repeat]] perpetually a direct thread (ihttp://ancientchess.e. perpetual check 長將, perpetual thread of capture 長捉, a check and then a threat of mate 一將一殺, or a combination of these)com/page/play-xiangqi. This needs htm How to be taken into account in the [[Play Xiangqi - Chinese Chess Board Representation|board representation]]</ref>.

=Pieces=Pieces on Cannon is the red side bear different characters than their counterparts on the black side. They are the same pieces, but names on the Red side are subtly more noble than those on the Black side <ref>[http://ancientchess.com/page/play-xiangqi.htm How to Play Xiangqi - most interesting piece in Chinese Chess]</ref>chess.

<span id="Engines"><Rules===Basic==Basic rules are similar to chess with some modifications. Pieces can move and capture according to their individual ability and restriction along the lines including the “Riverbanks”. Xiangqi doesn’t have rules such as castles, en-passants, promotions. Instead it has some limitations such as King, Advisors must move inside their own Palaces, Horses and Elephants can be blocked (from moving), two King cannot “face” each other (stands in the same column without any piece between). The object of the game is to [[Checkmate|checkmate]] or [[Stalemate|stalemate]] (is a win as well) the opponent King aka General. ==3-Folk Rules==When a position repeated 3 time (3 folks) the game will be terminated too. However, partly due to the freedom and power of the Rook over other pieces, and the limited freedom of the King, it is forbidden to [[Repetitions|repeat]] perpetually a direct thread (i.e. a perpetual check 長將, perpetual thread of capture 長捉, a check and then a threat of mate 一將一殺, or a combination of these). If no side violates the forbidden, game will be ruled as a draw. Ruling the game when 3 forks happen is the hardest thing for fully understanding, installing for both players and software. =Notations=* [[FEN]]: Chinese Chess can use [[Forsyth-Edwards Notation]] to save down positions, ignored some fields such as Castling and En passant target square. Here is FEN of the starting position: rheakaehr/9/1c5c1/p1p1p1p1p/span>9/9/P1P1P1P1P/1C5C1/9/RHEAKAEHR w - - 0 1 * [[Traditional Chinese Chess Notation]]* [[SAN]]* [[WXF]] =Programming=Chinese chess is quite similar to chess in multi-aspects thus its software can be developed and tested in similar ways. It can use almost all chess techniques, from traditional methods using [[Board Representation]], [[Alpha-Beta]] [[search]], [[Evaluation]], [[Opening Book]], [[Endgame Tablebases]]... to new ones using [[NNUE]], [[AlphaZero]] methods... However its programming is a bit harder to gain high levels due to some reasons: a) The board is significantly larger (90 vs 64, 40% larger) b) Even there’s no diagonal slide moves (such as Bishops), its pieces have more limitations, been blockable, Cannons have a special way to capture... The board size (90) can't fit 64-bit integer either, the number of columns 9 can't help quick devices... All may make move generators be more complex and slower c) The search trees are usually larger. For example, when comparing Perft results at deep 7, Xiangqi Variantsnumber is 72 times as large d) Evaluation of positions may require more knowledge, especially endgame positions e) Rules 3-fork repetitions are hard to implement and maybe so slow * [[Chinese Chess Board Representation]]* [[Chinese Chess Perft Results]] =Sub variants=

 =Xiangqi Engines=