I respectfully caution us against the casual habit of using the powerful word "principles" when describing chess opening theory that is based on deep experience with only the traditional start setup. I believe some of what we today call opening "principles" will eventually be exposed as being mere esoteric tactical considerations of the traditional setup.
I responded with links to a number of previous posts on that same subject.
- Knights before Bishops?
- Lasker on Basic Opening Principles
- Yusupov's 'General Principles of Opening Play'
- Fine's 'General Principles' of Opening Theory
It's also worth noting that opening principles that apply to the traditional start position (SP518 RNBQKBNR) weren't constructed from thin air, nor were they developed by sifting through the thousands of critical variations that arise from that position. They are based on the same considerations that guide a chess player throughout a game. I've listed these in an article that has nothing specific to do with chess960: Positional Play in Chess. They are
- The center,
- Open lines,
- Piece activity,
- Pawn structure,
- Strong and weak squares, and
- King safety.
If I wrote the same article today, I would add
- The initiative
which through years of playing chess (and chess960), I've come to appreciate more and more. That makes seven points, the same as the number of colors in a rainbow or the number of notes in a musical scale. There's something natural about the number seven that appeals to me.
Back to the list of four previous posts, GeneM picked up on 'Knights before Bishops?' and made another comment.
Reuben Fine listed his famous nine opening principle of chess in his book 'Chess the Easy Way'. But... From considering chess960-FRC, I believe that some of Fine so-called principles would be found to be merely esoteric tactical considerations of the particular start setup that has been traditionally reused since 1475; and those items from Fine's list would become less interesting when seen in the proper larger context of openings for many sensible start setups.
I assume that Fine's 'Chess the Easy Way' repeats the same points from his 'Ideas Behind the Chess Opening', which I listed in 'Fine's General Principles'. As with some of Fine's other principles, 'Develop Knights before Bishops' is a guideline specific to SP518 and not necessarily to all other chess960 start positions. The principle can be expanded to include all chess960 start positions by stating something like 'make the obvious moves first'. In SP518 the Knight jump to the long diagonal is generally better than either of the two alternatives. For the Bishops, the choice is not so clear. First there is the choice of which diagonal. Then there is a choice of squares on that diagonal.
One quarter of chess960 positions start with a Knight in the corner. The obvious move there is to develop the Knight to its third rank. The alternative, to the second rank, happens less frequently. Knights starting on the c-, d-, e-, or f-files often do not have such an obvious choice, partly because they have a choice of two good squares on the third rank.
For how many positions does the principle 'make the obvious moves first' reduce to 'Knights before Bishops'? We already know about SP518. We can also add SP534 RNBKQBNR, because the development patterns are identical to SP518. No doubt there are other SPs, but how many? What characteristics of initial piece placement do they share?
Other points on Fine's list lead to similar questions. Take, for example, 'Do not bring your Queen out too early'. I have played at least one game where early development of the Queen to the center was an excellent strategy. For sure there are other positions, but how many? What characteristics do they share? For me, answering questions like these are more critical than the tree of opening variations for a single start position. In the long run they will help me to understand chess better and to play a stronger game.