Hi All, I am currently conducting an experiment, in which I evolve game strategies with GP. I wanted to know if it is possible to alter the game board from within a function in the tree. My architecture is as follows (I don't know if it's the standrard in such cases or not...): 1) Class GPStrategy (extending GPIndividual) gets a copy of the game board (copied into ((Game)problem).input.board. 2) This class calls child.eval with the required params and returns the value (the boards' evalutaion) What I wanted to do is to have one of the tree functions move a piece on the board, perform some analysis, and then move the piece back. What is the best way to do so? Thanx in advance. Sincerely, Ami H.