Yesterday, I profiled a number-crunching addon that does the math to tell you about the actual effects of your abilities and spells. Therefore, I thought it appropriate to share this number-crunching macro. This is one I've only recently had to use. After a few hours debating the meaning and theory behind becoming uncrushable and uncrittable, I think this macro is a great tool for raid leaders and tanks alike.
Basically this macro adds up your total avoidance to determine whether or not you meet the sacred uncrushable numeral: 102.4% total avoidance.
Regardless of any arguments about the mechanics behind this system, its what is accepted as the way things are. If you're tanking, pushing Crushing Blows off the attack table is one of your primary goals. As a note, Druids cannot become uncrushable, sorry, you're stuck taking it like a bear.
Come back after the break so I can share the macro without cluttering the front page with scripting code.