The Snowroof opening was invented in the Edo period as well. It was popular in the first part of the 20th century but lost popularity after the 1940s and 1950s and was found only sporadically in professional games. However, recently, in 2017, the Snowroof has surged in popularity with professional players as a good strategy to combat opponents using Fortress strategies.
Over time the popularity of various opening theory has changed. For instance, the earliest games in the historical record were Black's Static Rook vs White's Ranging Rook. However, after the 8th Lifetime Meijin was appointed in 1744, Double Static Rook openings became the standard way due to the superior winning results of Static Rook over Ranging Rook at the time, and Ranging Rook openings were mostly abandoned. It was not until the beginning of the 20th century that Ranging Rook openings became more popular. The popularity of Ranging Rook gained more ground with high winning results 1950s–1970s from strong Ranging Rook player Yasuharu Ōyama.
Major changes in the rules of chess in the late fifteenth century increased the speed of the game, consequently emphasizing the importance of opening study. Thus, early chess books, such as the 1497 text of Luis Ramirez de Lucena, present opening analysis, as does Pedro Damiano (1512), and Ruy López de Segura (1561). Ruy Lopez's disagreement with Damiano regarding the merits of 2...Nc6 led to 3.Bb5 (after 1.e4 e5 2.Nf3 Nc6) being named for him as the Ruy Lopez or Spanish Opening. Opening theory was studied more scientifically from the 1840s on, and many opening variations were discovered and named in this period and later. Opening nomenclature developed haphazardly, and most names are historical accidents not based on systematic principles. In the early 1930s the nascent FIDE embarked on a project to standardize opening nomenclature, culminating in the publication of a short booklet in 1933, but this had little impact.
The opening principle of fighting for control of the center with both players pushing central pawns ☖...P-54 and ☗P-56 can be seen in older variations of Double Wing Attack opening. This way of playing was heavily researched and reached its pinnacle during 1790–1800 when the 9th Lifetime Meijin Soei Ōhashi wrote a book on it. Nowadays, this is considered old fashioned as control of the center is no longer emphasized in modern shogi theory. (Cf. Chess strategy§Control of the center.)
A few opening names are descriptive, such as Giuoco Piano (quiet game). More prosaic descriptions include Two Knights and Four Knights. Descriptive names are less common than openings named for places and people.
Chess players' names are the most common sources of opening names. The name given to an opening is not always that of the first player to adopt it; often an opening is named for the player who was the first to popularize it or to publish analysis of it. Eponymic openings include the Ruy Lopez, Alekhine's Defense, Morphy Defense, and the Réti Opening. Some opening names honor two people, such as the Caro–Kann.
The Ware Opening attacks the b5-square and prepares to bring the a1-rook into the game. The b5-square is non-essential and if Black plays 1...e5, the f8-bishop prevents the development of the white rook for the moment. The reply 1...e5 also gains space for Black in the center, a typical objective of most openings but one completely ignored by the Ware Opening. Noting all this, the Ware Opening is normally seen played only by players completely new to chess.
Some openings have been given fanciful names, often names of animals. This practice became more common in the 20th century. By then, most of the more common and traditional sequences of opening moves had already been named, so these tend to be unusual or recently developed openings like the Orangutan, Hippopotamus, Elephant, and Hedgehog.
An experienced player using the Ware Opening will usually meet a response of 1...d5 or 1...e5 with 2.d4 or 2.e4, respectively, since a reversed Scandinavian or Englund Gambit would be unsound here. After 1...d5 2.Nf3, 2...Nf6 is recommended, since a reversed Fajarowicz can arise after 2...c5 3.e4!? dxe4 4.Ne5 where a4 has some utility. At some point the move a5 will be played, followed by Ra4 (as Ra3?? invites ...Bxa3 leaving Black up the exchange).
Many terms are used for the opening as well. In addition to Opening, common terms include Game, Defense, Gambit, and Variation; less common terms are System, Attack, Counterattack, Countergambit, Reversed, and Inverted. To make matters more confusing, these terms are used very inconsistently. Consider some of the openings named for nationalities: Scotch Game, English Opening, French Defense, and Russian Game—the Scotch Game and the English Opening are both White openings (White chooses to play), the French is indeed a defense but so is the Russian Game. Although these do not have precise definitions, here are some general observations about how they are used.
The main openings in a repertoire are usually reasonably sound, that is, they should lead to playable positions even against optimal counterplay. Unsound gambits are sometimes used as surprise weapons, but are unreliable for a stable repertoire. Repertoires often change as a player develops, and a player's advancement may be stifled if the opening repertoire does not evolve. Some openings which are effective against amateur players are less effective at the master level. For example, Black obtains active play in return for a pawn in the Benko Gambit; amateur players may have trouble defending against Black's activity, while masters are more skilled at defending and making use of the extra pawn. Some openings which are played between grandmasters are so complex and theoretical that amateur players will have trouble understanding them. An example is the Perenyi Attack of the Sicilian Defense (see diagram) which yields an immensely complicated and tactical position that even strong players have difficulty handling, and that is beyond the comprehension of most amateurs.
Major League Baseball had most of its teams open the 2011 season on a Thursday (March 31) or Friday (April 1) rather than the traditional Monday, in order to prevent the World Series from extending into November. Similarly, most teams opened the 2012 season on Thursday (April 5) or Friday (April 6). However, subsequent seasons through 2017 returned to Monday openers for most teams. For the 2018 season, all 30 teams were scheduled to open the season on Thursday, March 29 (the earliest domestic start for a regular season in MLB history, and the first time since 1968 that all major league teams were scheduled to start the season on the same day, although two games were subsequently rained out and postponed to Friday, March 30). In 2019, MLB scheduled an even earlier opening day for most teams on Thursday, March 28; this excludes a two-game series on March 20 and 21 between the Seattle Mariners and Oakland A's at the Tokyo Dome in Japan.
The entry of athletes was followed by opening remarks by Rio 2016 Organizing Committee head Carlos Arthur Nuzman, who invited athletes to "play fair, abide by the rules and, most of all, have fun doing what you do best". The crowd booed at Nuzman after he thanked local governments for their contributions to the Games. Nuzman's speech was followed by a speech by IPC president Philip Craven, in which he called upon spectators to "see the true meaning of sport and the true definition of ability", explaining that "in a country which has faced major challenges of late, Paralympians will switch your focus from perceived limitations, to a world full of possibility and endless opportunity. They will surprise you, inspire and excite you, but most of all they will change you." The Games were officially opened by President of Brazil Michel Temer; in the wake of the formal impeachment of Dilma Rousseff, Temer was also booed at.
At the opening ceremony, the Japanese conductor Ozawa Seiji directed the fourth movement of the Beethoven Symphony No. 9 . The musicians come from five continents.
The opening ceremony included 'Ode to Joy' being sung.
After the speeches by Rio 2016 Organizing Committee President Carlos Arthur Nuzman and by IOC President Thomas Bach, Kenyan runner and two-time Olympic champion Kipchoge Keino ran up to the stage to receive the first Olympic Laurel award, accompanied by children flying 200 white kites shaped like doves. Earlier, children in Kenya inscribed messages of peace on the kites. At 23:27pm BRT, Brazil's Acting President Michel Temer recited the games' opening declaration from the stands in Brazilian Portuguese. Contrary to usual practice, he was not introduced at the beginning of the ceremony, nor was he introduced at the end of President Bach's speech.
With Bird's Opening White tries to get a strong grip on the e5-square. The opening can resemble a Dutch Defense in reverse after 1.f4 d5, or Black may try to disrupt White by playing 1...e5!? (From's Gambit).
The earliest full game record is a 1607 game between the First Lifetime Meijin (Black) and Hon'inbō Sansa (White). Black is playing a Right Fourth File Rook (Static Rook) position while White is playing a Fourth File Rook position. As the Ōhashi–Hon'inbō games are Ranging Rook games, it is believed that these two significantly developed the opening theory.
In morphological opening, erosion operation removes objects that are smaller than structuring element B and dilation operation restores the shape of remaining objects. However, restoring accuracy in dilation operation highly depends on the type of structuring element and the shape of restoring objects. The opening by reconstruction method is able to restore the objects completely after erosion applied. It is defined as the reconstruction by geodesic dilation of n erosions of F by B with respect to F :
While there are numerous variations most opening credits use some variation of the basic order. In the absence of opening credits, these roles will often be credited in reverse order at the beginning of the closing credits.