Pro Pool originated in December with 800 units being fabricated. This add-a-ball machine was designed by Ed Krynski with artwork by Gordon Morison. Two replay versions of the game were also made: a two-player version called Big Shot and a four-player version called Hot Shot. Obviously the theme of this game is the game of pool. The playfield is symmetrical and the way to win extra balls is by completing the left and/or right drop target battery. Doing so will lift the left and/or right wow rollovers for this award. The drop targets reset once the sequences are completed. Of course, an operator-adjusted score is another way to score a couple of balls. Back in the ‘70s, multiple balls or replays could be achieved on the game. Today, one free game on a current solid-state game is the common win. Operators have made it harder to achieve free games today as free games yield no income and only result in down time for the machine to earn coins in the till.