cavalier (fr), Problema del caballo (sp), Problema do cavalo (por), Springerproblem (ger), חידת מסע הפרש (he), 騎士巡邏 (ch), ナイト・ツアー (jap).     Introduction   The ' knight ' (♘ ♞, colloquially, horse ) is a piece in the game of chess, representing a knight. But unlike the other chess pieces , it