

I can provide you with a link to a firemage raid simulator I wrote, if you want. PPS: For raids it gets really complicated. PS: Factors in the talents that increase fire damage by a certain percentage have no effect on the relation between crit and spellpower. So, I don’t know the gear of our lvl 50 firemage in question here but if he has less than 300 spelldamage then crit is likely worth less than 9 SP. Rank 12 Fireball also increases the value of crit compared to spellpower, as it increases the base damage. That means 1% crit is now worth 9.385 spellpower. If your mage has 300 spellpower already then your fireballs hit for 938.5 damage. So, given a naked mage, 1% crit equals 6.385 spellpower. To increase your damage by 1% with spellpower you need 6.385 spellpower. (Independent of how much damage your fireball actually does). That means 1% more crit increases your average damage by 1%. To make matters worse, the Critical Hit Damage stat is hard-capped at 150 for a follower. The Scoundrel can sport up to 23.8 Critical Hit Chance, and the Enchantress can have 22 Critical Hit Chance. Let’s assume that a crit doubles the damage (in fact it multiplies the damage by 1.5 and then multiplies that by 1.4 because of ignite - we assume only one spell is cast so no interaction with other spells - 1.5 x 1.4 = 2.1 so in fact crit is actually a bit better than just doubling the damage). With all possible item slots prioritized for critical hit chance, he can have around 34 Critical Hit Chance. The average damage of a fireball is (561 + 716) / 2 = 638.5 damage. Ignore the 72 damage over 8sec, that does not get affected by spellpower or crit. Hurls a fiery ball that causes 561 to 716 Fire damage and an additional 72 Fire damage over 8sec. Ok let me get out my maths… let’s just look at crit and spellpower for now. I get the conversion from 8 int to 1% crit (as you need roughly 60 int for 1% crit as a mage) but I don’t get why 1% crit translates to 9 SP. Where do you come up with these numbers? XD *Crit roughly doubles the damage for fire with ignite and it doubles the damage for frost with whatever the talent is called. In general I prefer to go for +hit and spelldmg and just take +crit in addition to that (I value it at roughly 10 spelldmg as Bigkeg says) but that’s just my personal preference. In raids there’s the additional consideration that ignite stacks (one stack per target and not per player) so if 5 mages get a fireball crit and that ignite ticks for 3000 damage (and they manage to keep the stack alive for a while) that’s a ton of additional dps caused by even just an ignite crit that keeps the stack alive. On average that’s 1125, more than the 1000 damage your fireball dealt with 100% crit or with 500 spelldmg. If you got 50% crit and 250 spelldmg instead, half your fireballs deal 750 and the other half deal 1500 damage. If your fireball deals 500 damage with 0% critrate by default then 100% crit doubles* that damage and 500 spelldmg double that damage. The more crit you have, the better spellpower becomes. The more spellpower you have the better crit becomes. Well, for PvP it’s hard to say… for PvE it’s like this:
