I think few folks dispute a grade on a coin that they submit that comes back graded higher than they expected. Perhaps they would for an obviously worn coin that comes back with a MS grade. So, how often do wrongly high grades appear on slabs? The TPGs may have run some quality assurance tests to monitor it, but if so, I doubt the results will be made public. I suspect this kind of error is uncommon, especially for high-end coins that may get extra scrutiny by finalizers after slabbing. Still over time, it probably does contribute a little to gradeflation. And it's one more reason to look at the coin and not just the slab label when buying. Cal
