Martin Gardner (I think) once suggested playing tic tac toe by instead having the two players choose integers from the set 1,2,3,4,5,6,7,8,9, the first player to obtain a sum of fifteen winning. The magic square 2 9 4 7 5 3 6 1 8 then proves useful. My question: does anyone know a way to make tic-tac-toe, or something like it, into an interesting game? My sons, 5 and 7, are always wanting to play it and I'm suffering. I'm too strong at dots and boxes to play them with enjoyment. Here's a problem for an idle moment: How many essentially different "cat" positions (ie, fully played-out draws) are there in tic-tac-toe with best play, if we regard two as the same under a rotation or reflection of the board? Thane Plambeck 650 321 4884 office 650 323 4928 fax http://www.qxmail.com/home.htm