What is meant by openings with lot of theory versus those with little or none? I just started playing chess one week ago. I've done a bit of reading but can't find anything that explains what is meant by openings with a lot of theory versus ones with a little or no theory. Can this be explained in
a &quot;chess for dummies &quot; language?
In chess, &quot;opening theory&quot; or just &quot;theory&quot; means &quot;established opening lines&quot;: usually lines that have been studied and judged to lead to more or less equal positions, and appear in books.
It's unfortunate terminology since it matches neither the day-to-day meaning of the word (something that's contrasted to practice) nor the meaning used in game theory. But we're stuck with it.
While &quot;opening&quot; sometimes refers to a specific line, it's better to think of it as a game tree, that is, a collection of lines with a common origin. Openings with &quot;lots of theory&quot; are those with large game trees. This is usually a combination of two factors: long lines (the tree is deep) and lots of variations (the tree is wide, with a lot of branches).
Openings that are popular among top players will be studied more so will tend to have longer book lines. Openings that lead to positions with a lot of good moves will have lots of variations, while openings with forced moves will naturally have fewer variations.
In short, openings with lots of theory are those with more pages in opening books.
For example, Mastering the Chess Openings devotes 75 pages to the Sicilian Opening, and only 10 to the Caro-Kann. So we could say that the Sicilian has more theory than the Caro-Kann. Of course, different books will give you different numbers, but you get the idea.