I’ve been thinking about Piece-Square tables. They’re not the most exciting part of computer chess but they seem quite important (based on Ed Schroder’s experiments), so I thought I’d put some time into thinking about reasonable values. I’ve created a simple spreadsheet in Excel to help create them. You can download it here (Piece-Square-Tables.xlsx). It assumes your board representation starts with A1 = 0 and H8 = 63.
Here’s how to use the Excel spreadsheet:
- The worksheet is protected to prevent accident overwrites. You can unlock it easily as it’s not password protected
- Enter the values in the yellow squares on the left. The gray squares are the mirror image of the yellow squares.
- The table in the middle is adjusted to make the average table value zero. This means if I set the value of a bishop to be 350 centi-pawns and put it on a random square, the value returned by the Piece Square Table will average out to 350 centi-pawns. The idea is to minimize interaction with other evaluation terms.
- The column to the far right is the table formatted as a “C” array. You can copy and paste this code.
Here’s a screenshot: