The Oxford Companion to Chess lists 1,327 named openings and variants, and there are many others with varying degrees of common usage.
These include preparing pawn breaks to create counterplay, creating weaknesses in the opponent's pawn structure, seizing control of key squares, making favorable exchanges of minor pieces (e.g. gaining the bishop pair), or gaining a space advantage, whether in the center or on the flanks.
[13] The main openings in a repertoire are usually reasonably sound; that is, they should lead to playable positions even against optimal counterplay.
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.
[5] 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.
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.
Many openings are named after nationalities of players who advocated them, for example Indian, English, Spanish, French, Dutch, Scotch, Russian, Italian, Scandinavian and Sicilian, or places where important games featuring the opening were played such as Vienna, Berlin, and Wilkes-Barre.
Bird's Opening, 1.f4, addresses center control but not development and weakens the king position slightly.
Worse possibilities either ignore the center and development such as 1.a3, weaken White's position (for instance, 1.f3 and 1.g4), or place the knights on poor squares (1.Na3 and 1.Nh3).
One reasonable way to group the openings is: The Indian systems (1.d4 Nf6) are the most important[22] of the semi-closed games, and warrant separate treatment.
This is the most popular opening move and it has many strengths—it immediately works on controlling the center, and it activates two pieces (the queen and a bishop).
The Philidor Defense (2...d6) is not popular in modern chess because it allows White an easy space advantage while Black's position remains cramped and passive, although solid.
The Pirc and the Modern are closely related openings that are also often seen, while the Alekhine and the Scandinavian have made occasional appearances in World Chess Championship games.
The Sicilian and French Defenses lead to unbalanced positions that can offer exciting play with both sides having chances to win.
Alekhine's, the Pirc and the Modern are hypermodern openings in which Black tempts White to build a large center with the goal of attacking it with pieces.
Also, compared with the King Pawn openings, transpositions among variations are more common and critical in the closed games.
Both of these moves lead to an immense forest of variations that can require a great deal of opening study to play well.
Both systems are popular with club players because they are easy to learn, but are rarely used by professionals because a well-prepared opponent playing Black can equalize fairly easily.
The Stonewall is characterized by the White pawn formation on c3, d4, e3, and f4, and can be achieved by several move orders and against many different Black setups.
As with the closed games, transpositions are important and many of the Indian defenses can be reached by several different move orders.
Black's most popular replies are: Advocated by Nimzowitsch as early as 1913, the Nimzo-Indian Defense was the first of the Indian systems to gain full acceptance.
Black attacks the center with pieces and is prepared to trade a bishop for a knight to weaken White's queenside with doubled pawns.
Although it was played occasionally as early as the late 19th century, the King's Indian was considered inferior until the 1940s, when it was taken up by Bronstein, Boleslavsky, and Reshevsky.
Distinguished by the move 3...d5, Grünfeld intended it as an improvement to the King's Indian which was not considered entirely satisfactory at that time.
The Modern Benoni is a risky attempt by Black to unbalance the position and gain active piece play at the cost of allowing White a pawn wedge at d5 and a central majority.
If White accepts the gambit, Black's compensation is positional rather than tactical, and their initiative can last even after many piece exchanges and well into the endgame.
The King's Indian Attack (KIA) is a system of development that White may use in reply to almost any Black opening moves.
Its greatest appeal may be that by adopting a set pattern of development, White can avoid the large amount of opening study required to prepare to meet the many different possible Black replies to 1.e4.
Although some of these openings are not actually bad for White, each of the twelve remaining possible first moves suffers one or more of the following defects compared to the more popular choices: 1.Na3: Durkin 1.a3: Anderssen 1.b3: Nimzowitsch-Larsen 1.Nc3: Dunst 1.c3: Saragossa 1.d3: Mieses 1.e3: Van 't Kruijs 1.Nf3: Zukertort 1.f3: Barnes 1.g3: Benko 1.Nh3: Amar 1.h3: Clemenz