Originally Posted by
Shahad
You don't get what they are saying.
DKs deal with randomness in their rotation in the form of the level 75 talents (except blood tap). You can get lucky and proc Runic Empowerment more than 45% of the time for example. It's only over a large amount of time that it averages out to 45% proc rate. There are other RNG source too, such as the procs of Killing Machine, crits, Rime procs, etc that all contribute to making each one of your attempts vary substantially from each other.
SimCraft sims your character with the normal proc rate(I.E. 45% for Runic Empowerment) and gives you the result. It's possible you get really lucky and get KM procs on 70% of your Frost Strikes, and that every Obliterate grants a Rime proc. But SimCraft ignores these, because they are very unlikely.
So maybe you got lucky on your first dummy test, and then you had bad luck on the second.