06 June 2010

Move Order in the Opening

If the only consideration in the opening was to Count the Developing Moves, chess would be an easy game. Every good player knows that, when developing the pieces at the beginning of the game, careful attention has to be paid to move order.

In the traditional start position (SP518: RNBQKBNR), we take for granted that two minor pieces must move before castling to either side is possible, and that the Queen must move before castling O-O-O is possible. In chess960, those considerations are different for each start position. In the worst case, positions like RKxxxxxR, five pieces must move before castling O-O is possible, while in RxxxxxKR five pieces must move before O-O-O is possible.

In SP518, we have guidelines like Knights before Bishops, when the best developing square for a Knight is often more obvious than the best square for a Bishop. In other chess960 positions, the best square for a Knight is not at all obvious and may depend on the opponent's initial moves.

Some time ago, in A Framework for Chess960 Opening Theory,
I noted that the different SPs can be classified and analyzed generically depending on which files the pieces are initially located. It turns out that the framework is useful in chess960 for counting the developing moves and for determining best move order.

The development of the pieces can't be taken individually. A good example is the family of positions like BxNxxxxx (or their twins xxxxxNxB), where White should be wary of Nc1-b3 (Nf1-g3 for the twins), blocking the movement of the b-Pawn and the opening of the diagonal for the Bishop on a1. If White has already played b2-b4 (g2-g4), the move Nc1-b3 (Nf1-g3) is perfectly logical. Similar considerations, usually more subtle, come into play for every chess960 opening.

05 June 2010

Count the Developing Moves

In Chess Openings : Count the Developing Moves, I discuss a useful device for measuring progress in traditional chess.
Starting from the initial position, the minimum moves you need to develop your game completely are:-

* 2 Pawn moves to let the Bishops out
* 4 Minor piece moves
* 1 Queen move
* 2 Rook moves, developed to a center file
* 1 King move, usually by castling, more often by O-O than by O-O-O

That makes a total of 10 developing moves. This holds for both sides, whether you're playing White or Black. Looking at it another way, you start the game with eight pieces. On their original squares the pieces are undeveloped. You need to make at least one move with each piece plus two Pawn moves for the Bishops. That makes ten moves.

The count isn't perfect, because it ignores some common situations. For example, developing the Queen often requires another Pawn move, and castling is not always so straightforward. Sometimes castling develops both the King and Rook immediately. More often a second move is required to develop the Rook (after O-O) or to safety the King (after O-O-O). Despite its inaccuracies, the count is useful to compare the deployment of your army relative to your opponent's.

I've found that counting the development moves is also useful in chess960. There are, however, several different considerations. I'll cover some of these in future posts.