considered essential, so a Unity Pool organisation was created for the seven largest pools companies to produce joint coupons. Treble Chance The Treble Chance game was inaugurated in 1946. Players were given a list of football matches set to take place over the coming week and attempted to pick a line of eight of them, whose results would be worth the most points by the scoring scheme; traditionally by crossing specific boxes on a printed coupon. A proportion of the players' combined entry fees was distributed as prizes among those whose entries achieved the highest scores. Prior to this the Penny Points and Penny Results were the most popular games. The Treble Chance offered a potential large jackpot at a time when no other form of gambling in the United Kingdom did. Some pools offered additional ways to win, based on scores of football matches at half-time, or football matches in which a particular number of goals were scored. By 1947, pools revenue had increased to £70 million a year, with over 90% being spent with Littlewoods, Vernon's, Sherman's and Cope's. It accounted for almost 15 million postal packets each week through the post office. By the 1950s, 100,000 people were working in the industry. Agreement with the Football League In July 1959, the High Court of Justice ruled that the Football League owned the copyright to their fixture lists and this led to a 10-year agreement between the pools companies and the English and Scottish Football Leagues, whereby the pools companies would pay the leagues 0.5% of the stakes received (or a minimum of £245,000 per year). During the 1972-73 season, the deal between the Football League and the pools companies was extended for 13 years worth £23 million. Off-season With professional football not being played in the United Kingdom during the summer, Zetters introduced Australian pools, based on games played in Australia. Mechanics Entries Entries were traditionally made by post, or via agents or collectors who received a percentage (usually 12.5%) of the money as a fee. Main collectors, who appointed the agents, delivered the forms and payments to a regional office, which were then dispatched to the companies' central offices. Legally the football pools collectors were agents of the entrants, not the pools company. Business for pools collectors was sustained by periodic canvassing, where company agents knocked on doors in an area of a town or housing