I'm now thinking about adding more pawn structure related terms to my evaluation, however terms that only depend on the pawn structure are limited. The king pawn shelter could be a pawn structure related term but it depends also on the king position. The same pawn structure will produce a different results for the shelter depending on the location of the king (after king side or queen side castling). Only if I add the king position to the hash I can evaluate the pawn shelter. But there is a downside. The amount of hash hits and so the efficiency of the cache will decrease.
In order to visualize the effect I selected a number of positions and recorded the number of hash hits with and without including the king positions in the hash.
|Successful hash hits with and without king positions in the hash|
I have to try it out.