The term 'Boundary Racetrack' refers to a racetrack that is located on the boundary between two different jurisdictions. The crossword solutions for this term are RAIL (4 letters), ODDS (4 letters), and TOUT (4 letters). RAIL refers to the physical track that horses race on, ODDS refer to the likelihood of a horse winning a race, and TOUT is someone who promotes or advertises a horse in order to increase its chances of winning.