How exactly are Class Changes Done?

Ghostcrawler posted the other day a somewhat detailed explanation as to the reasoning and methodology that Blizzard follows when changing classes. The massive Death Knight nerf is what spawned this particular thread.

We have spreadsheets — huge ones. We have values for characters in greens and raid buffed with epic gear. We have estimates of mob damage and health, character downtime, the benefits from enchants, gems and glyphs. We have conversion rates of mana to runic power to energy to rage. We look at damage per second, efficiency, button presses per second, typical rotations, movement vs. standing still, mobs vs. players and every other variable we can think of (and there are a LOT of them).

In the end we come up with an estimate for what an attack should do. We come up with a budget for talents and spells just like we have a budget for items at a given level. Sometimes those estimates are wrong because we forgot to take something into account, or because there’s a bug in a talent or spell somewhere that messes up the calculation.

And then we do lots of testing, and to get a reality check on our tests, we compare them to the numbers people are reporting from the beta. Repeat as necessary.

I’ve said this in a few posts: that our numbers can sometimes be wrong (as is the case almost any time you deal with numbers), but the methods we use to arrive at them are absolutely not sloppy. (src)

Typically I would agree 100% with Blizzard. They’ve proven to be more right than wrong in the past and I’d like to take solace in the mentality that the people in charge of my favorite hobby (and a rather significant part of my life now) know what they’re doing. I won’t go into detail on how I feel about the complete and utter anal reaming Death Knights received in this latest patch.