In particular these graphs include shaman slow.  Cleric stun isn't included, because it doesn't work on mobs anyone would want to fight in a group at level 60, plus in almost all cases, healing is superior to stun.  Ro and Cripple aren't included because the damage reduction is difficult to predict.

As was mentioned in the Intro, these graphs show the damage per second mitigated by the priest at different points in time.  The first graph for example shows that clerics can mitigate about 170 damage/sec at the 600 second mark.  This means that for a tank to die, when supported by this cleric, it will need to take more than 170 damage/sec for 600 seconds to overcome cleric healing.  How much damage is needed at any time interval to outdamage the healer is exactly what these graphs show.

For the shaman line, the shaman casts slow and keeps it active on the mob.  To simulate resists, the slow cast time and mana cost is increased by 20%.  All healing done by the shaman is multiplied by 4, to simulate 75% slow.  I.e. if a mob could do 400 dps normally, then slowed it will only do 100 dps, and 100 dps of shaman direct healing, when combined with the slow, will result in 400 dps mitigated.  If this concept is confusing, I recommend getting a PEZ dispenser.  It should be entertaining for hours.

The first graph shows mitigation capability without the newly added mini-CH spells.  This is mostly of academic interest (for all those academics that study EQ), but I leave it here anyway.  The later graphs are more useful, and representive of practical application.

Update 10/21/02 Since some dispute the 40% mana reduction figure, I've added a new graph showing mitigation capability with no mana reduction of any kind.  This way, those that feel 40% is too great can look at the 0% graph and the 40% graph and choose values in between the two, to get a fairly good approximation of whatever mana reduction value they feel is best.

The above assumes Turgur's lasts its full duration, which is useful when solo or fighting boss mobs, but isn't accurate in a normal experience situation.  To simulate this, the next two simulations assume Turgur's lasts 1 and 2 minutes respectively.

This sim shows mitigation capability using the spells available at level 65, according to the spdat at the time of writing.  The particular spells used are the new self buffs for druids and clerics that adds a couple of points of mana regen, and the new high effeciency no-penalty torpor spell, Quiescence, for shamans.

NOTE: these graphs, and all graphs showing level 65, refer to level 65 spells only.  The priests are still effectively level 60.  They don't have increased mana or hp.  They don't have increased mana regen.  They don't have any new PoP caster improvement AA's.  They're level 60 priests that somehow can cast level 65 spells.

Commentary

Why are shamans so good?  It isn't any one thing.  Slow certainly plays a major role, since it effectively multiplies other shaman healing by four, but it's more than that.  It's also shaman mana regeneration, which is far superior to any other class in the game, easily twice as good as necromancers.  That mana regen exists because of Torpor, Cannibalize IV, and Cannibalization.  Without Torpor, the mana regen would be significantly less.  Without Cannibalization, the time cost of shaman mana regen would be much higher.

It's every ability, not just added together, but multiplied, that makes shamans into the powerhouse shown above.

Of course, not all mobs are slowable.  Next, we'll take a look at Healing Only, which is pure healing, ignoring slow.