http://www.wowwiki.com/ParrySwing timer
After a successful parry, the defender's "swing timer" is reduced by 40% of your weapon speed (or even reset), unless this would result in a reduction to less than 20% of your swing time remaining. This results in an average of .24 extra swings per parry; thus parry favors slower, higher damage weapons.[1] Note that with a slow weapon and fast incoming attacks, it is possible to gain multiple speed reductions. While tanks like to profit from this effect, melee damage dealers should attack from behind whenever possible, both to increase their own damage and to avoid causing unneeded damage to the tank through the enemy's parries.
насколько это актуальная информация?