the Idea is to look at the starting grade as well... Ones that start at A5 mean:

A5: Authenticated Bat with Noted Evaluation of Usage and/or Player Characteristics

I have a Ty Cobb bat that went from an A5 to A8 due to significant usage.

Such things as chipped knob, dings, and lack of a picture/factory record (40k) knocked it down a bit. But all those things dont change its original starting point of an A5.

Where you get A2's and A1's is where things get a little more chancey, as noted in there description.

Some have suggested that there be a Provenance Grade, then a Condition Grade...

Like An A5 and an A6 for each...