public static int addValue(int r, int c, DraughtsState ds) {
        int piece = ds.getPiece(r, c);
        if (piece == DraughtsState.WHITEFIELD || piece == DraughtsState.EMPTY) {
            return 0;
        }
        if (piece == DraughtsState.WHITEKING) {
            return 50 
                    + KING;
        }
        if (piece == DraughtsState.WHITEPIECE){
            return calcPlayground(r, c, true) 
                    + DRAUGHT;
        }
        if (piece == DraughtsState.BLACKKING) {
            return  -50 
                    - KING;
        }
        if (piece == DraughtsState.BLACKPIECE){
            return -calcPlayground(r, c, false) 
                    - DRAUGHT;
        }
        return 0;
    }