71 Pa. Stat. § 720.63
A licensed racing entity conducting pari-mutuel wagering shall display on video screens the approximate odds or approximate will-pays on each horse for each race as well as a combination of races, including, but not limited to, quinellas, exactas, perfectas and any other combination or pool of races. A display of approximate odds or approximate will-pays is not required where the wager is on horses in four or more races, such as Pick 4, Pick 5 or Pick 6. In addition to displaying the amount of money wagered, the approximate odds or approximate will-pays on each horse or combination of horses must be shown on video screens in each wagering division. For trifectas, in lieu of odds or approximate will-pays, the amount of money being wagered on each horse to win in the trifecta pool must be displayed on video screens separately from any other information. Information must be displayed from the opening of bets or wagering and be continually displayed until the wagering is closed. At least one video screen in each wagering division shall display the amount of money wagered on each horse involved in a trifecta pool.
71 P.S. § 720.63