O
pening theory is a fascinating thing. I refer, with these words, to the beginning stages of a strategy game, in which the players are essentially "setting up" the ambience of the conflicts that will come to define the middle game. Go and Chess have very different approaches to each of these stages, and consequently the conversation about opening theory is rather different within the communities.
First of all, the openings themselves take on varying character because Chess is fundamentally a subtractive game, while Go is an additive game. In chess, you never have more pieces than you do on the first move, and they will slowly drain away across the course of the game. Meanwhile in Go, you have no pieces on the board before the first move, and the vast majority of pieces that are placed on the board will still be there by the end. What this means is that in Go, the opening is the most open part of the game -- simply speaking, there are the most number of possible moves in the beginning of the game. In Chess, exactly the opposite is the case -- as the board thins out, the number of possible moves (in general) increases. From the start, we can already make some assumptions about the characters of the openings of these games -- probably Go's will be freer, and probably Chess's more restrictive.
This turns out to be roughly correct. However, the interesting thing is how coming to understand the opening feels within the two games. In Go, opening theory is practically disposable until the higher reaches of the game. It is simply put, extremely difficult to gain a significant advantage in the opening. It can happen, but typically via a blunder from one's opponent. Joseki, the sequences of movements that occur regularly in corners, have some semblance to the opening theory of Chess, but they are far more "optional" than Chess's lines, and easier to turn to simple variations which might come with a small cost of efficiency, but which will almost certainly be drowned out by the forces of the middle game. Until one is extremely skilled, the opening simply doesn't matter very much.
In Chess, on the other hand, misplaying an opening can be absolutely catastrophic. Being down even one pawn, with no compensation, is considered to be a serious disadvantage in Chess (whereas in Go, even losing 10 pieces with no compensation can be overcome with some determination). Chess, it is often remarked, is fundamentally a tactical game. Strategic considerations of course exist, but they tend to be subtle, and difficult to grasp at a level that can affect the course of play until, again, the higher reaches. What this means is that an increasingly-encyclopedic knowledge of opening lines is virtually required to perform in chess at even an intermediate level. The penalty for not knowing an opening is simply too high.
Personally, I actually think that the term "theory" is inappropriate for Chess, simply because one is memorizing rather than understanding. This situation, I believe, comes about because the Chessboard is so thick with intersecting piece-threats, each of which is so threatening to the balance of the game, that abstract considerations cannot come immediately come into play -- raw tactical survival is what matters the most, which can be calculated by computers and memorized by human minds. I don't think theory is exactly the right term for this system. Theory ought to involve learning principles, and then learning how and when they should be applied to particular situations (endgame theory in Chess is a perfectly good example of this).
At the end of the day, this is why the highest level Chess players in the world tend to get bored and frustrated with Chess. Memorization stops being fun pretty quickly, but it takes up more and more of the top players' minds as the lines expand. Which is precisely why, for example, Magnus Carlsen wants to shift the top Chess world over to Freestyle/Chess960/Fischerrandom Chess.
This will probably take another post to explore, but I find Freestyle Chess absolutely fascinating, both from the perspective of player and observer, but also conceptually. It points to a deep tension within the game of Chess, which doesn't really exist within Go (it's worth noting that the number of Go professionals complaining about Go as a game is basically zilch). There's something about the pieces themselves that speaks to the heart of the game -- in Chess, slowly killing off complex, embodied pieces; in Go, slowly adding more and more faceless, homogenous stones. It delights me that such pure, but different games can exist at the same time.