#0 - July 1, 2010, 1 a.m.
According to MMO, when you max out protection's masteries with 51 points, the chance for a crit block to occur becomes...26.01%.
...Ugh? That IS a placeholder, right? For those that don't know how crit block works, it's an rng chance to proc an extra block on top of an RNG block (which is going to be between ~10-20% chance already, minus unblockable attacks/magic).