Evaluation Function
- With tic tac toe, it's easy. You know the result, 1, 0 or -1, and
you can pass those values up. It's pretty easy to get to the
bottom (it's only 9 ply or moves at most).
- With chess or checkers, you can not easily get to the end of the
game.
- So, you have to heuristically evaluate the board.
- What is the value of a chess board?
- Win, lose and draw are obvious, but unusual.
- How can you tell the value of a board?
- The pieces, and power of the pieces are a good start.
- However, there are a lot of other things involved including,
but not limited to, promotable pawns, control of the centre,
knight centredness, and passed pawns.
- You also want the evaluation function to be fast (so you
do more searching.)
- Some other things you might want to check out are Alpha Beta Pruning,
and iterative deepening.
