Here some more inportant information show to you ,hope can help you in Diablo 3 game my darling :)

1.Shield is just a perpugnation about the player,to continuation defense or not to be ,just see the face .So it's defense defense seems as one kinds of lower hide.
2.The shield defense effect base on your damage,the high frequency the damage is lower,the effect is better.
3.Parry is later than all damage reduction effect of calculation, so the higher resistance armor, you can shield block and the higher the damage.
4.According to top, Parry how much damage can be equivalent to you how much less some blood.
5.Good shield is very great, in the best condition (a pile of small strange dozen you, every time off blood than block value), 1,2,3,6 are stronger than shield evade power word (or double the passive, and ran ray boxing), 6 shield is equivalent to 25% of the extra dodge.

6.With a single damage increase, shields attenuation quickly, can let you to single out more than 20000 blood the threat, temporarily not a shield can provide more than 5% of the average reduction, for can kill you damage second, no matter what the shield gap is not large, less than three percent.

7.Simply say the top saying: for can let you off more than 20000 disposable blood attack, shields basically didn't what effect.
8.If from the shield characteristics: in small damage for, block value gap is not big, high block shield effect significantly better rate.

The summary:
The shield against high frequency small damage is very good, block rate more than 17% of the shields are more at least equal to a dodge truth. For the second high damage, block basic useless (armor or shield real). Shield block rate is very important, less than 17% of the block rate you sell it.