Sunday, December 30, 2007

Pawnstructure and piece activity

This is going to be a weird post. Because I want to find out some chess fundamentals I take matters to the extreme. I don't care that some positions aren't even possible in a game. I take Rybka as the final judge of every position. Which is questionable but as close to objectivity as I can get.

Diagram A

White to move

The pawnstructure is symmetrical. If there were no bishops Rybka would score it 0.00 in the end. No advantage from the pawnstructure alone exists. I experiment with extreme piece placement in order to get some insight in the influence of pawnstructure on piece activity. In the position above Rybka scores +0.12 for white. Indicating that the pawnstructure has about equal influence on both bishops, no matter their initial placement. If I use bishops of different color makes no difference too, no matter where I place them. If it was black to move in the position above it would score -0.10 for black, suggesting some hindrance of black's bishop. The figures are very marginal and posibly near to zero if you let Rybka calculate long enough.

Diagram B

White to move

Rybka scores this as +1.09 for white. If it was black to move Rybka scores it -0.40 for black.
This indicates that two items play a role:
  • The existance of weaknesses (targets)
  • The tempos needed to conquer them
In the position above the weaknesses are b2 and b7, but white has immediate access while black must play his bishop to f4-c1 first, spoiling two tempos. This leads to the following conclusion:

Piece activity is only relevant in relation to targets. Without targets pieces are going nowhere, no matter how mobile they are.

The fact that this obvious law dwelled in obscurity so long is that when you improve the mobility of your pieces the chance improves that an accidental coming into existence of a target will be beneficial for you. That obscures matters and gives the impression that mobility in itself is an asset. But it is of course better to know what you are doing instead of waiting for targets to appear accidentally. Again a plea for target consciousness.

The level of activity of a piece can maybe be expressed in tempo's to target.

My posts often come as a surprise to me, Dear Reader.