Electronic Chess Piece Divination. Oakland: Bob Koch/Koch Magic, ca. 1984. Six chess pieces (three white, three black; two rooks, two pawns, and two knights) are removed from a fine hardwood box one at a time and concealed in the pockets of six different spectators. The magician instantly knows which piece is held by which spectator. Box finely crafted from exotic hardwood. 9 ? x 3 ? x 3". Working, with internal electronic system. One of less than ten manufactured. With instructions. Near fine condition. RARE.