[Sennex]

Reading up on the Parry formula, I came across this note on WoWwiki.

NOTE: When a mob parries an attack, its swing timer also advances in the same manner. This does not apply to certain Raid bosses for which parry-haste functionality has been explicitly turned off by the game designers, e.g. Brutallus.

Is it posted anywhere specifically what bosses this has been turned off for?

[Satorri]

There are only tests saying that some are, and Blizz has actually specifically mentioned others.

The only current ones I'm aware of for sure are Patchwerk, Thaddius, and Ignis. Though there are others I'm sure.

[Heladys]

Didn't they recently make it clear that Gormok had parry-hasting disabled?

[Bashal]

Source: Heladys Didn't they recently make it clear that Gormok had parry-hasting disabled?

As I recall, they hotfixed a "bug" where Gormok's parry haste was accidentally left on. So he did have parry haste, but no longer.

[Pylae]

/agree with Gormok

Anyone know if it's active on either Koralon or Kologarn?

[Sennex]

I don't "think" its enabled on either, as I haven't noticed it, but could very well be wrong, I haven't tanked it allot on my warrior, and never actually tanked it on my DK. Although tomorrow that might change (God I hope!)

[Satorri]

I'm fairly certain (as you cannot get behind him) that Kologarn does not parry haste, but I've never actually parsed logs to be sure.

Koralon I wouldn't assume though.

[GravityDK]

Vezax doesn't parry-haste either. Splug worked it out once.

[Satorri]

I didn't think we had ironed that out reliably enough to be confident.

[Bashal]

Source: GravityDK Vezax doesn't parry-haste either. Splug worked it out once.

Source: Satorri I didn't think we had ironed that out reliably enough to be confident.

Yeah, it appeared to be that parry haste was turned off, but it wasn't definitive. Although it would be reasonable if it was the case, as Vez is a hard-hitting boss and parry haste can RNG any tank into oblivion in that kind of encounter.