So what do I need?
- A 64-bit random number generator which will populate 12 145-element arrays (for each piece of each colour).
- A total of 16 Zobrist keys for castling and turn combinations (I really only need 5, but using an array lookup like this will be cheap. All I need to do is to do a lookup, based on the board's status flag, which is a 4-bit value).
- A total of 16 Zobrist keys for e.p. squares.