GNU Shogi manual: Mating problems

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Differences between shogi and chess

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-Some differences between shogi and international chess have been -mentioned elsewhere in this document; I summarize them here for people -who are interested in game comparisons. I won't try to deal with the -thorny question of which game is "better" although my bias may have -already come through :-) In fact, the drop rule makes the two games so -different in character that arguing over which game is better is like -comparing apples to oranges (you'd be better off comparing chess to Chu -shogi (see section Shogi variants). However, I believe that if you are a -chess fan you'll really like shogi as well, and shogi is also popular -with many people who don't particularly like chess. - - -

-Here are the significant differences between chess and shogi: - - - -

- -In shogi, captured pieces become the property of the capturer and can -re-enter play by being dropped onto almost any vacant square. In chess, -captured pieces are out of the game. Thus, in shogi, piece exchanges -complicate the play significantly while in chess they simplify it. - -
- -The shogi board is 9x9; the chess board is 8x8. - -
- -Shogi has five pieces with no counterpart in chess: the gold and silver -generals, the lance, the promoted rook and the promoted bishop. Chess -has one piece with no counterpart in shogi: the queen. The knight's -move in shogi is much more restrictive than in chess. Pieces in shogi -generally have a much smaller range of movement than in chess (unless -they are in hand). - -
- -In shogi, all pieces except the gold general and the king can promote, -but only to one kind of piece. Promotion is easier in shogi because the -promotion zone is closer to the starting position of the pieces -(especially pawns). In chess, only the pawn can promote, but it can -promote to any other piece except the king. - -
- -In shogi, pawns capture the same way they move. There is no initial -two-space pawn move and hence no en-passant captures. In chess, -pawns capture diagonally which means that opposing pawns can block each -other. + + + + + -
- -In shogi, you only have one rook and one bishop. Note that the bishop -is not restricted to only one "color" square (squares in shogi aren't -colored, but never mind) because promoted bishops can also move one -square orthogonally. - -
- -There is no special castling move in shogi. The term "castle" is -used in shogi to denote a defensive formation consisting of (usually) -three generals which protect the king. There are many such castles -(about 40 or so have names). See section Sample game. - -
- -Draws are much rarer in shogi than in chess. Perpetual check is not -allowed. Stalemate is a virtual impossibility, and is a loss for the -stalematee. - -
- -Since pieces are never out of play in shogi, chess-type endgames -involving only a few pieces do not occur. - -
- -Shogi games are generally longer than chess games (about 60-70 moves is -typical). - -
- -Shogi has a well-developed handicap system which is in general use; -chess does not. - -

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2.3 Mating problems

-The effects of all these differences on play include (in my opinion): - - - -

- -Piece/pawn structures in chess are more rigid than in shogi. Pawns -block each other and pawns, once advanced, cannot ever retreat. In -shogi, you can repair the hole caused by a pawn advance by exchanging -the pawn and dropping it back where you want it. Thus shogi is more -fluid than chess and less "structural". - -
- -Counterattack is MUCH more common in shogi than in chess. Games -typically end in mutual mating attacks, where each player is trying to -checkmate the other player before being checkmated himself. This makes -tempo incredibly important and also makes sacrificial play quite common. - -
- -Attacks involving only ranging pieces are more a feature of chess than -of shogi. A shogi attack typically uses a ranging piece or pieces to -support an attack by short-range pieces (especially generals). It is -very rare to mate a king with a non-adjacent ranging piece in shogi -since the player whose king is threatened can almost always interpose by -dropping a piece. - -

- [Contents] [Back] [Prev] [Up] [Next] [Forward] +One good way to improve at shogi is to solve mating problems. There are +several types of these problems, but the most common is called a +"tsume-shogi" problem, or "tsume" problem for short. In a tsume +problem, all pieces that are not on the board are assumed to be in the +opponent's hand (except for your King, which is usually not shown). +Every move you make must be check until the final checkmate. Your +opponent may play any piece on the board or drop any of his pieces in +hand in order to prevent the mate. In a properly constructed tsume +problem, all of your pieces on the board and in hand must be essential +to the solution. One consequence of this is that all of your pieces in +hand must be played during the solution. There should only be one +correct solution for the given number of moves. Tsume problems use +Japanese-style move numbering; thus, a problem where you move (and give +check), your opponent moves, and you move to give checkmate is called a +three-mover. Here is a really trivial three-mover: +

+ + 3 2 1
+----------------+
+| | | | a
+----------------+
+| | | wK | b
+----------------+
+| | | | c
+----------------+
+| bN | | | d
+----------------+
+| | | | e
+----------------+
+| | bN | | f
+----------------+
+

+ +Black in hand: S, G +

+ +Here, Black plays G*2b, White plays K1c, and Black plays G*1d mate. +More typical tsume problems range from 5 moves to arbitrarily high +numbers of moves, and they can be quite brain-busting. Tsume problems +may seem artificial, but in the closing stages of the game where both +players have a lot of pieces in hand, it is often necessary to give +check at every move, or else your opponent will start a counterattack +and will mate you before you mate him. A tsume problem is a worst-case +scenario for the attacker: you have to mate your opponent even though he +has every piece not on the board in hand, which means you have to +develop sharp attacking skills. Many more tsume problems can be found +on the internet; I particularly recommend Patrick Davin's "Shogi +Nexus" (see section 5. References and links). +

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