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Shogi Opening Sequences
Below is a list of the more common initial opening move sequences found in professional shogi games. First move Out of the 64,046 recorded (mostly) professional games on Kyokumenpedia (局面ペヂィア) as of 2019 Jan 23 spanning the timeframe from the 1600s to 2018, 77.2% started with a bishop pawn opening (P-76) and 20.8% started with a rook pawn opening (P-26). The rook pawn push naturally leads to Static Rook openings; however, it is possible to play a Feint Ranging Rook as well. The bishop pawn push is more flexible and thus more ambiguous about the planned opening information given to White. A less common first move (1.6% of Kyokumenpedia games) is the king's pawn (P-56). This move often suggests a Ranging Rook opening ( Central Rook or Opposing Rook) for Black. Other first moves are relatively rare and occur less than 0.5% of the time. For instance, the fourth most frequent move is the left edge pawn (P-96), but this only occurs less than 0.1% of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shogi Opening
A shogi opening ( ) is the sequence of initial moves of a shogi game before the middle game. The more general Japanese term for the beginning of the game is ()''.'' A '' jōseki'' () is the especially recommended sequence of moves for a given opening that was considered balanced play at one point in time for both sides by professional players. (However, some ''s'' have become outdated when they are reevaluated to no longer give balanced play.) ''s'' also typically include commentary about the possible reasons to deviate from the especially regarding blunders. Note that not all openings have ''s''. For example, trap openings like Demon Slayer, while they may have standard moves, are considered to favor one player and are not balanced play. Thus, the Demon Slayer opening is not a jōseki. Introduction The very first opening moves in most games are pawn pushes. In particular, most games start with two types of pawn pushes. A player can move the rook pawn forward (P-26) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Natural Logarithm
The natural logarithm of a number is its logarithm to the base of the mathematical constant , which is an irrational and transcendental number approximately equal to . The natural logarithm of is generally written as , , or sometimes, if the base is implicit, simply . Parentheses are sometimes added for clarity, giving , , or . This is done particularly when the argument to the logarithm is not a single symbol, so as to prevent ambiguity. The natural logarithm of is the power to which would have to be raised to equal . For example, is , because . The natural logarithm of itself, , is , because , while the natural logarithm of is , since . The natural logarithm can be defined for any positive real number as the area under the curve from to (with the area being negative when ). The simplicity of this definition, which is matched in many other formulas involving the natural logarithm, leads to the term "natural". The definition of the natural logarithm can then b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bishop Exchange
In shogi, Bishop Exchange (角換わり or 角換り ''kakugawari'') is a Double Static Rook opening in which the players exchange their bishops relatively early so as to have bishops in hand. Throughout the game, both players have a bishop drop threat, with which they can exploit any positional weakness that their opponent inadvertently creates. Overview The Bishop Exchange opening is a Double Static Rook opening. Black starts with activating both their bishop (P-76) and rook (P-26) while White quickly puts pressure on Black with rook pawn pushes (...P-84, ...P-85). White's aim is to exchange their rook pawn off the board on the eighth file as soon as possible. This has a number of benefits: it gives White a pawn in hand that can be used to drop later in the game, and it frees up the rook so that it can move to any rank above Black's camp (see: Sabaki). However, in this opening, in response, Black wishes to prevent White's early rook pawn exchange by defending the 86 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aphorism
An aphorism (from Greek ἀφορισμός: ''aphorismos'', denoting 'delimitation', 'distinction', and 'definition') is a concise, terse, laconic, or memorable expression of a general truth or principle. Aphorisms are often handed down by tradition from generation to generation. The concept is generally distinct from those of an adage, brocard, chiasmus, epigram, maxim (legal or philosophical), principle, proverb, and saying; although some of these concepts may be construed as types of aphorism. Often, aphorisms are distinguished from other short sayings by the need for interpretation to make sense of them. In ''A Theory of the Aphorism'', Andrew Hui defined an aphorism as "a short saying that requires interpretation." History The word was first used in the '' Aphorisms'' of Hippocrates, a long series of propositions concerning the symptoms and diagnosis of disease and the art of healing and medicine. The often cited first sentence of this work is: "" - "life is shor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ishida (shogi)
The ''Ishida'' Opening (石田流三間飛車 ''ishida-ryū sankenbisha'' or shorter form 石田流 ''ishida-ryū'') is a major variation in Third File Rook openings of the Japanese game of '' shōgi''. In the Ishida Opening, in contrast to other Third File Rook openings, the seventh file pawn is advanced to the fifth rank if played by Black (P-75), or the third file pawn if played by White (P-35). This allows the rook to move up to the 76 square (Black) or 34 square (White). History The variation is said to have originated with a blind ''shōgi'' player named Kengyo Ishida in the early Edo period. Although records of Ishida's actual games still exist, all of them end in Ishida's loss. An extant game record of a Double Ranging Rook game in 1649 featuring an Ishida position played by Kengyo Ishida is shown in the diagram. A renaissance of the Ishida variation occurred in the 1970s through the development of an original strategy by the well-known ''shōgi'' master Kōzō Masud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snowroof
In shogi, Snowroof or Snow Roof Fortress (雁木 ''gangi'', lit. 'goose-wooden') is a Static Rook opening that characteristically uses a Snowroof castle. It is named after the covered sidewalks (雁木造) connected to buildings in Niigata Prefecture. Originating in the Edo period, the opening had been a less common one after World War II although it was popular in the prewar era. However, around 2017, the opening has become popular with professional shogi players. The Snowroof structure often appears in computer shogi games. Characteristics For Black, this castle positions the king on the 69 square while two golds are at the ears of king (78, 58) and the two silvers are on 67 and 57. The Snowroof castle is strong against attacks directly from above, especially attacks around the central file. Naitō (1981) notes that the Snowroof was once very popular and had a reputation for being very difficult for a Fortress opponent to defeat. However, by 1981, the Snowroof ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fortress Opening
Fortress (矢倉 or 櫓 ''yagura'') is both a Static Rook opening (矢倉戦法 ''yagura senpō'') and a castle in shogi. It is usually played in a Double Static Rook opening, which is often a Double Fortress opening. However, it may also occur in different Double Static Rook openings such as Fortress vs Right Fourth File Rook. The Fortress castle (矢倉囲い ''yagura gakoi''), which is the defining characteristic of Fortress games, was considered by many to be one of the strongest defensive positions in Double Static Rook games in the 1980s. The term ''yagura'' is the Japanese word for a tower-like structure in traditional Japanese castles. Double Fortress The most commonly encountered Fortress strategies occur in Double Fortress games where both players use a Fortress formation. Historical Fortress Earlier josekis for Fortress in the Edo period (usually spelled 櫓 at that time) were very different from the current josekis. For instance, in one variation, it is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fourth File Rook
In shogi, Fourth File Rook (四間飛車 ''shikenbisha'') is a class of Ranging Rook openings in which the rook is initially positioned on the fourth file if played by White or the sixth file if played by Black. History The earliest recorded shogi game was a Static Rook vs. Fourth File Rook game from 1607. Black was who played a Right Fourth File Rook position (Static Rook) against Sansa Hon'inbō's Fourth File Rook. Ōhashi won the game. Fourth File Rook vs Static Rook Normal Fourth File Rook The opening starts by the usual 4-move sequence that characterizes Static Rook vs Ranging Rook games as shown in the first adjacent board position. (See: Normal Ranging Rook.) Fujii System The Fujii System is a set of Fourth File Rook strategies used against various Static Rook strategies (mainly Left Mino and Bear-in-the-hole Static Rook). vs Rapid Attack Tateishi Fourth File Rook A Fourth File Rook opening created by amateur player Katsuki Tateishi, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Third File Rook
In shogi, Third File Rook (三間飛車 ''sangenbisha'' or ''sankenbisha'') is a class of Ranging Rook openings in which the rook is positioned on the third file if played by White or the seventh file if played by Black. Types There are two basic forms of Third File Rook. The first form is similar to other normal Ranging Rook openings such as Fourth File Rook. Here, the bishop is moved to the 77 square (Black) or the 33 square (White) often in order to prevent a Static Rook opponent's pawn exchange on the eighth (or second) file. The other Third File Rook form is known as the ''Ishida.'' In contrast, the seventh file pawn (Black) or the third file pawn (White) is pushed up to the fifth rank. This gives an option for the Ishida Third File Rook player's rook to be positioned on the 76 square (Black) or the 34 square (White). Furthermore, Third File Rook positions can be categorized according to whether the bishop's diagonal is open or closed. In normal Third File Rook and normal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transposition (chess)
In chess, a transposition is a sequence of moves that results in a position which may also be reached by another, more common sequence of moves. Transpositions are particularly common in the opening, where a given position may be reached by different sequences of moves. Players sometimes use transpositions deliberately, to avoid variations they dislike, lure opponents into unfamiliar or uncomfortable territory or simply to worry opponents. See review at In chess the verb "transpose" means to shift the game onto a different opening track from which it started. Transposition tables are an essential part of a computer chess program. Transpositions exist in other abstract strategy games such as shogi, Go, tic-tac-toe and Hex. Examples Positions reached by different routes For instance, the first position can be obtained from the Queen's Gambit: :1. d4 d5 :2. c4 e6 :3. Nc3 Nf6 But this position can also be reached from the English Opening: :1. c4 e6 :2. Nc3 Nf6 :3. d4 d5 so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Log Probability
In probability theory and computer science, a log probability is simply a logarithm of a probability. The use of log probabilities means representing probabilities on a logarithmic scale, instead of the standard [0, 1] unit interval. Since the probabilities of Independence (probability theory), independent event (probability theory), events multiply, and logarithms convert multiplication to addition, log probabilities of independent events add. Log probabilities are thus practical for computations, and have an intuitive interpretation in terms of information theory: the negative of the average log probability is the information entropy of an event. Similarly, likelihoods are often transformed to the log scale, and the corresponding log-likelihood can be interpreted as the degree to which an event supports a statistical model. The log probability is widely used in implementations of computations with probability, and is studied as a concept in its own right in some applications of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shogi
, also known as Japanese chess, is a strategy board game for two players. It is one of the most popular board games in Japan and is in the same family of games as Western chess, ''chaturanga, Xiangqi'', Indian chess, and '' janggi''. ''Shōgi'' means general's (''shō'' ) board game (''gi'' ). Western chess is sometimes called (''Seiyō Shōgi'' ) in Japan. Shogi was the earliest chess-related historical game to allow captured pieces to be returned to the board by the capturing player. This drop rule is speculated to have been invented in the 15th century and possibly connected to the practice of 15th century mercenaries switching loyalties when captured instead of being killed. The earliest predecessor of the game, chaturanga, originated in India in the sixth century, and the game was likely transmitted to Japan via China or Korea sometime after the Nara period."Shogi". ''Encyclopædia Britannica''. 2002. Shogi in its present form was played as early as the 16th century, while ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
