How good you are at football based purely on your ability. So your first touch, ball control, IQ, dribbling ability and how you can work in tight spaces.
These are numbered from 1 being the highest, getting lower as the numbers progress. With 1 being the highest Tier, mostly of those with a 90 and above.
Yes. Although unlikely for older players, for younger one with a high ceiling, there is a greater chance of this improving.