The Division allocations in ISA are simple. Schools in Div 2 only field one team per age group. These schools are generally limited by their smaller enrolments. There is no 2nd XV comp and several schools have insufficient players to field teams in one of the U13-U16 age groups therefore speculation that any Div 1 schools are in line for relegation is untrue unless the school plans on fielding one team per age when dropping to Div 2. St Pats are definitely safe in Div 1.
The decline in participants in many schools rugby programs has resulted in no school moving up to Div 1 from Div 2 in more than 10 years. St Augustine's and St Greg's went straight into Div 1 when they joined ISA based on their teams being too strong for Div 2 and their ability to field B teams. Chevalier and then St Andrew's dropped down from Div 1 to Div 2, leaving seven schools in Div 1.
Whilst less competition games provided opportunities for trial matches v CAS and GPS schools, Div 1 schools were left with a short season consisting of 7 competition rounds (only 6 games) where one loss often cost teams the premiership. Issues existed around home advantage, refs etc when schools only played opponents at home every second year. With the potential for washouts and byes, younger teams and lower grades often had less than 6 comp games which is difficult to sell to players and parents as a "season of rugby". In the past the short season length has been a significant issue in players choosing to play club rugby or league over schoolboy rugby which has meant that the best talent has not always played for their schools or in ISA rep teams. Some schools supplement their 1st XV season with Waratah Shield participation to increase the number of competitive games, however, the demise of that competition is discussion for another thread.
The change in structure of the CAS and GPS to home and away comps meant that there was no opposition to play from other associations in early Term 2 and ISA needed to extend their competition season. A home and away season was not possible with 7 schools as it includes a bye round and would go for 16 weeks which is longer than the 12 weeks allocated for the winter season. The combining of Pius and Greg's into one line facilitated the 6 line home and away season where schools received 5 home and 5 away games. This involved a huge amount of goodwill from both St Pius and St Greg's as only one school has the opportunity to play 1st XV and A games.
Out of the 10 rounds in this season's competition Kinross, Stannies, Pats, Oakhill and Augies had ONE round (away v Gregs/Pius) where they needed to send squads to different venues requiring them to send teams with reserves. The situation isn't ideal for the away team but as it only occurs once in 10 rounds it is fairer than the suggestion that Pius or Greg's should alternate hosting duties which would result in both schools playing either 7 or 8 games out of 10 away and possibly hosting only 2 rounds.
The 2016 format, whilst not perfect, resulted in a better season for players in the ISA Div 1 comp through better grading (safer for participants and more competitive) and extending the comp season by 4 games. Some comps, including 1st XV were not decided until the last round. Pius 1sts (a strong team by Pius standards) were not unbeaten in the 2nds comp however, the best indicator of the success of the format is if there is a reduction in mismatches in the lower grades which appears to be significantly less than previous years (certainly for St Greg's and Pius). Should the 2016 format be retained in the future it should assist schools to attract and maintain players to play rugby in the ISA comp simply through a greater number of competitive games that are better matched.