Ironically, the main task of chess software companies today is to find ways to make the program weaker, not stronger, and to provide enough options that any user can pick from different levels and the machine will try to make enough mistakes to give him a chance.
How Life Imitates Chess: Making the Right Moves, from the Board to the Boardroom (ed. Bloomsbury Publishing USA, 2010) - ISBN: 9781596918276