The Trunzos self-published the game, with help from Jim Barnes, who had founded the Statis-Pro line of sports simulation games. 'There really wasn't a decent representation of our favourite sport, pro boxing,' Jim Trunzo recalls of the decision he and his brother made in the late 1970s to create a game in which players flipped cards to simulate a fight, rather than use the dice or spinners that were prevalent in sports simulations of that era.