So I understand this shield has a block effectiveness of +364, plus another attribute of -50% block effectiveness, so the change when equipped is +70 block effectiveness then -50% block effectiveness (currently have 294, new item has 182 equipped).
But this is a game not a math exam, so how about making this easier by removing the whole -50% thing and just give this item 182 block effectiveness. Then the change when equipped would say -112 block effectiveness.
It’s not telling you the shield has 50% less block effectiveness than your previous shield…
The 50% less block effectiveness doesn’t apply directly to the shield. It applies to any block effectiveness you have, be it from affixes, buffs, mastery passives, specializations and, yes, the shield’s stat as well.
The ITEM doesn’t have 182 block effectiveness, YOU have 50% LESS.