Okay then, here goes a potted history leading up to the advent of the 73 changes.
In the post war sporting boom of the 1950s RL, along with other sports, saw a massive increase in attendances at all games, not just cup games. With people relaxing after the war and a distinct lack of home entertainment other than radio, few people had television, live sport was the entertainment of the day.In the period between 1952 - 62 CC semis managed 5 attendances over 5k, 6 over 40k, 9 over 30k none under 20k.In June 1961 the RFL announced that a 3 season experiment would take place, starting in 62/63 the league would split into two divisions.In 62 the semis attracted an average of just over 37.5k in 63 that halved to just over 18.5k, however the 63 semis came after the big freeze of Dec 62- March 63, the first signs of a thaw were in Feb 63 and things were getting back to normal come March, there was a backlog of games to sort out but the Semi-Finals went ahead on April 22nd 1963 long after the weather had improved.The following two seasons (63/64 - 64/65) saw an improvement in attendance (Av. 28k and 24k) but in December 63 Bradford were set to fold and in January 64 they did. Also in January 64 there was a proposal put forward to change the two division P&R from 2-up, 2- down to 4-up, 4 down after just one season of the experiment. Could this return to favour for the semis have been anything to do with the announcement In Feb 64 that the experiment was to be abandoned at the end of the season (announced around the time of the second round of the cup). If it did it was short lived as the attendances for 66 and 67 only averaged around 17k.Following the ups and downs of the early 60s the late 60s and the early 70s saw a rising trend in 72 the average attendances for the semis were 25k.In January 72 there was concern about the falling attendances at games in general and Wakefield and Hunslet were in financial trouble.This was also around the time of the Cain report which proposed 3 divisions with the 3rd division including the best amateur teams. The three divisions was rejected at a later meeting but clubs decided to investigate, nothing new is there, splitting the league half-way through the season, this was being proposed as a possible interim before a move to two divisions.Eventually they settled for one division with fixtures arranged on an East West split as was the case a few years earlier.In January 73, two divisions were back in favour, with reports that most clubs were in favour of the change. On Feb 16th 1973 the clubs voted for two divisions split 16 - 14 with 4-up, 4-down P&R. Once again around the time of the second round of the challenge cup two divisions was voted in. The 1973 semis fell to a post war low of average 14,698 only to be topped by 1974 which delivered a mere 9,880.
Thanks Padge - as always, an interesting read.