Right?

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).

Don't put much faith in those numbers.