For prot ratings, I have found it helpful to use multiple scales which tell me different things about the gear I am examining. I personally have five different scales right now: Avoidance, Full Avoidance, Block Value, Crit Reduction, and Health. I use the scales to help me determine which gearset a piece of gear should go into (threat, avoidance, high health, etc), as well as (particularly right now while leveling) to see what I need to have in order to become crit-immune again (by comparing the "crit reduction" on the new piece to the one I am replacing).
I have the scales set up such that the number I see actually corresponds directly to a real quantity. IE, the pawn value I see on the "Full Avoidance" scale will be numerically the % dodge, miss, and parry that the piece provides me. The "Health" value is the number of hitpoints the piece should give me. Etc. I find that this system helps me distill the key quantities out of the gear that I pick up while still maintaining enough granularity for me to be able to make intelligent decisions about gearing.
For those interested, here are the scales I use and how I derived them. For rating conversions, I'm using the data posted in the
prot field manual thread. Any stats not listed in any given scale can be assumed to be given zero weight.
Avoidance
This scale will yield a total % avoidance (miss+dodge+parry+block) given the amount of each stat
Note: this scale counts blocks. See the next scale for the full avoidance weights.
Agility: 52.08 agility = 1% dodge; 1 Agility =
0.0192 points
Dodge Rating: 39.35 dodge rating = 1% dodge; 1 Dodge Rating =
0.0254 points
Parry Rating: 49.18 parry rating = 1% parry; 1 Parry Rating =
0.0203 points
Block Rating: 16.29 block rating = 1% block; 1 Block Rating =
0.0614 points
Defense Rating: 25 defense (25*4.92 = 123 defense rating) = 1% each miss, dodge, parry, block; 1 Defense Rating =
0.0325 points
Full Avoidance
This scale will yield a total % full avoidance (miss+dodge+parry) given the amount of each stat
Agility: 52.08 agility = 1% dodge; 1 Agility =
0.0192 points
Dodge Rating: 39.35 dodge rating = 1% dodge; 1 Dodge Rating =
0.0254 points
Parry Rating: 49.18 parry rating = 1% parry; 1 Parry Rating =
0.0203 points
Defense Rating: 25 defense (25*4.92 = 123 defense rating) = 1% each miss, dodge, parry; 1 Defense Rating =
0.0244 points
Block Value
This scale will yield the total amount of block value present
Note: Assumes 5/5 Divine Strength and 3/3 Redoubt
Block Value: 1 block value = (1)*(1.3) block value; 1 Block Value =
1.3 points
Strength: 1 strength = (0.5)*(1.15)*(1.3) block value; 1 Strength =
0.7475 points
Crit Reduction
This scale will yield a total % reduction in the number of incoming critical strikes given the amount of each stat
Defense Rating: 25 defense (25*4.92 = 123 defense rating) = 1% crit reduction; 1 Defense Rating =
0.0081 points
Resilience Rating: 81.97 resilience rating = 1% crit reduction; 1 Resilience Rating =
0.0122 points
Health
This scale will yield the total amount of hit points that the piece will provide
Note: Assumes 2/2 Sacred Duty and 3/3 Combat Expertise
Stamina: 1 stamina = (10)*(1.06)*(1.06) = 11.236 health; 1 stamina =
11.236 points
Health: 1 health = 1 health;
1 Health = 1 points
For sockets, I make the assumption that I will put a standard gem in each socket. At the moment, while leveling, I don't care to invest in blue gems; therefore I weight the sockets in each scale as if they contained my green gems of choice:
[Solid Chalcedony] (blue socket),
[Enduring Dark Jade] (yellow socket), or
[Sovereign Shadow Crystal] (red socket). I just multiply the appropriate stats on those gems by the weightings above, sum it, and use that as my socket weighting.
Unfortunately, this can cause problems. When viewing an unsocketed item, Pawn now gives you the option to either match socket colors properly or to "smart gem" the sockets such that you obtain the most points (on that particular scale) by treating sockets as the highest value color and taking into account the value of socket bonuses. The problem with this second method is that it causes conflicts between scales. Pawn will assume a full set of "red" socketed gems for the Block Value scale, as the red socket is the only socket that has any rating on that scale. Same for "yellow" socketed gems on the avoidance scales. Obviously, since both can't occur at the same time, it gives numbers for the values of each scale that are skewed upwards too much.
The way to avoid this issue is to tell pawn to always socket by socket color (to match socket bonuses). (This is a global option for each scale that has an option box which appears when you click on a socket color to set its weight.) That way, I can always assume a given socket has the gems I set above and Pawn will give me accurate weights.
EDIT: When using the scales above, make sure you set Pawn to round to 2 or 3 decimal places of precision when calculating weights. Otherwise, you end up with items rounded to a whole percent of avoidance/etc, which isn't all that useful. (Ideally, you would have a precision of 1 for the BV and Health scales, and 0.01 for the avoidance and crit reduction scales. Unfortunately, I haven't found a way to set precision per each scale, only a global option.)