Grading of shaft

[Straight strike]

How is grade AAA shaft differ from grade A's? Is it in terms of grain pattern or playability? Who set these standards, by wood suppliers or the cuemakers themselves?

[sunny3909]

Quality of wood is set by the cuemaker as most of the top cuemakers select their own wood from the suppliers,Grading depends upon on rigidity,spring,stiffness and grain pattern on the ash.