the very Yank practice of slabbing.Aidan.
I see nothing wrong with the 70 point grading system.It cam from the grading of large copper cents. Thus aMS-70 coin penny was worth 70 times what a Basal state 1 was worth.Of course, this was a long time ago.
The true purpose of todays 70 or even a possible 100grade range is money. TPG make a loving from regradesand the more points to play with, the more money flowsin.A major problem with the 70 point system is the enormousjumps in price values we see between two numbers. I havereally not understood why one point miight be 4X as much difference in price. I suppose condition rarity might play a role.