Mr. Silverman has either presented, revised or improvised some 100 problem games for two players which might be something simple from your childhood--well, not Postoffice--but Ghosts or Quick-Tac-Toe or various board games (Scrabble) or chess or bridge or poker. Even some more dangerous ""Life Games"" and they offer really challenging stumpers sometimes depending on mathematical skills. For Martin Gardner's graduates, intellectual sport for those with high I.Q. men.