2 entries in Cards / Principles / Pointer Anomaly
  
Creators Title Comments & References Source Page Categories
Martin Gardner MG Trio #3 orientation of head on QS and KH used for monte type guessing game, turning on vertical or horizontal axis ("The principle behind this trick has floated around a while.")Variations Prototype 20
Robert E. Neale Heads Turn orientation of head on picture cardsInspired by Prototype 22