Openings
What does irregular opening mean in chess?
- Opening
- Plans
- Move Order
Irregular opening: Early 19th-century chess literature classified all openings that did not begin with either 1.e4 e5 or 1.d4 d5 as "irregular". As opening theory developed and many openings previously considered "irregular" became standard (e.g. the Sicilian Defense), the term gradually became less common. Opening books today are more likely to describe debuts such as 1.
Irregular opening FAQ
What does irregular opening mean in chess?
Irregular opening: Early 19th-century chess literature classified all openings that did not begin with either 1.e4 e5 or 1.d4 d5 as "irregular". As opening theory developed and many openings previously considered "irregular" became standard (e.g. the Sicilian Defense), the term gradually became less common. Opening books today are more likely to describe debuts such as 1.
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