Accessing Material Imbalance Information?

[Joost Buijs]

I use 40 bit for the material index as well.

With a mask operation I detect positions which have no more than 3 knights, bishops, rooks or queens for each side, if this is the case it is very simple to calculate a 24 bit key which I use as an index into a 16 MB. table with scaling information, positions with more than 3 pieces of each type are always scaled 100%.

The only problem is to fill the scaling table with useful information, in practice most of the entries in the table are also set at 100%.