Tanking stats scaling with level

1000 spell damage at lvl 60 is exactly as effective as spell damge at lvl 70. It increases all of your spells by that static figure, modified by the individual spell/rank. 1000 AP at lvl 1 is exactly as effective as 1000 AP at lvl 80. It increases your melee dps by (1000/14). +Healing acts similarly. Granted, this is not the case for all healing.dps stats. Spell crit/hit, melee crit/hit, penetration, expertise all, I think, suffer from becoming less effective at higher levels. But the guts of these players' effectiveness, the raw damage/healing bonus from direct stats, stays the same.

This is not the case for tanking. Non-threat Tanking stats fall into two main categories: avoidance and effective health. Both of these suffer immensely from level scaling, avoidance moreso. Avoidance suffers because it consists entirely of ratings. Dodge, parry, defense. These suffer at higher levels. Block rating, too, suffers, but its limited usefulness lessens this particular blow. Effective health suffers because armor, one of the contributing stats to the player's total effective health, and a multiplier of sorts at that, becomes less effective at higher levels.

The result of this is basically that a level 70 wearing full tier 3 would not be nearly as effective against a raid boss as a level 60 wearing the same gear. Even if one only considers avoidance, the scaled value of these stats is only slightly offset by the small bonus to avoidance/block given by level difference.

There are, however, two stats which are static, and remain consistent regardless of level. These two stats have the effect (on the assumption that, for the sake of argument here, tier 2 is as good for level 60s as tier 5 is for level 70s in terms of AC mitigation and avoidance) that a lvl 70 t5 tank would have a much easier time tanking tier 2 content than a level 60 t2 tank. These stats are stamina and block value.

Stamina always turns into the same amount of health. At its base rate, 1 stamina = 10 health. Always. At level 1, at level 255. The effect of this in the t2/t5 example above is simply that a t5 tank has much more stamina, and consequently has around double the EH of the t2 tank, which would make healing immensely easier.

Block value shaves a set amount from all blocked attacks. At higher levels, the only difference is that more block value becomes available. Higher level bosses hit harder; with a comparable AC mitigation rate (which is always limited to 75% regardless of level), and comparable avoidance and block rates, the only way for a higher level tank to deal with this extra damage is with his/her higher stamina and block value.

The other side of this is the marvellous soloing of old-world content we are capable of. Comparable AC/avoidance/block rate. Higher stamina (considerably less consequential in this example). High block value. As it happens, compared to level 60 gearing, quite remarkably high block value. With effort uncrushable against this content is reachable, and at that point the only limit to what melee bosses you can solo is your block value.

When level 80 we all reach, (look as good you will not, hmm?) assuming this gearing trend continues, expect to be able to solo a lot of TBC's (now conveniently nerfed) melee bosses.