Editing Chess opening (section)

==Opening repertoires==
{{Chess diagram
| tright
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|rd|nd|bd|qd|kd|bd|__|rd
|__|pd|__|__|__|pd|__|pd
|pd|__|__|__|__|nd|__|__
|__|__|__|__|pd|pl|pl|__
|__|__|__|pd|__|__|__|__
|__|__|nl|__|bl|ql|__|__
|pl|pl|pl|__|__|pl|__|pl
|rl|__|__|__|kl|bl|__|rl
|The [[Perenyi Attack]] (1.e4 c5 2.Nf3 d6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 a6 6.Be3 e6 7.g4), position after 7...e5 8.Nf5 g6 9.g5 gxf5 10.exf5 d5 11.Qf3 d4. This attack has been played several times between grandmasters, but chess author Lars Bo Hansen does not recommend this to amateurs.}}

Most players realize after a while that they play certain types of positions better than others, and that the amount of theory they can learn is limited. Therefore, most players specialize in certain openings where they know the theory and that lead to positions they favor.<ref name=Reper/> The set of openings a player has specialized in is called an opening repertoire.<ref name=Reper>{{cite journal|title=Measuring Chess Experts' Single-Use Sequence Knowledge: An Archival Study of Departure from 'Theoretical' Openings|last1=Chassy|first1=Philippe|last2=Gobet|first2=Ferdinand|year=2011|volume=6|issue=11|pages=e26692|journal=[[PLOS One]]|doi=10.1371/journal.pone.0026692|pmid=22110590|pmc=3217924|bibcode=2011PLoSO...626692C|doi-access=free}}</ref> The main elements a player needs to consider in a repertoire are:
* As White, whether to open with 1.e4, 1.d4, 1.c4, or 1.Nf3
* As Black, a defense against any of these openings

A very narrow repertoire allows for deeper specialization but also makes a player less flexible to vary against different opponents. In addition, opponents may find it easier to prepare against a player with a narrow repertoire.<ref>{{cite book|last=Webb|first=Simon|title=Chess for Tigers|publisher=Oxford University Press|year=1979|isbn=0-7134-8988-X}}</ref>

The main openings in a repertoire are usually reasonably sound; that is, they should lead to playable positions even against optimal counterplay. Unsound [[gambit]]s 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 that 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 played between [[International Grandmaster|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.<ref name="won and lost"/>