What was the reason for introducing it?
It was introduced to avoid a 44 game league calendar, and apparently to make the league more exciting, as top teams play top for euro places, bottom team fighting to avoid relegation, etc.
To be frank, however it's crazy, Rangers this season have to play 3 games away from home consecutively as a result of it, and i'm convinced Celtic would have an opinion it, but for the fact they're already at war with the SFA.
There is also another league format on the table, which involves something like the top 8 teams in the SPL splitting to fight for, Euro places, but their points being reset, and the bottom four teams joining with the top four teams from the first division , and fighting for the chance to play in the SPL next year with their points also being reset.
The format mentioned above isn't a bad idea, certainly can't be worse than our current system, though i'm noot keen on it, as by doing this we would have the most complicated league set-up in Europe.