if you want the perfect system, it has to be one that evolves, and allows new fans on to the system, without alienating those who have done the time, and this is what i would do, even though it would not benefit me at all.
basically i would make the loyalty points a 5 year cycle (or similar time frame), basically only the points from the last 5 years at any one time count.
our system has been in place for 7 years now, so the points awarded in the first 2 years of the system would now have expired, but obviously if you continue to go you are maintaining your position, but those lapsed supporters from the start of the system would be effectively overtaken by the next generation, thus allowing them dibs at the big games.
hope that makes some semblance of sense.