Duplicate: Better Than "The Pros" Expected

When Curse of Naxxramas cards were being announced, there was some discussion over the mage secret Duplicate. A number of well-known players talked it down, saying it was ultimately "a bad card that seems good".

I've held the opposite opinion of Duplicate since I first saw it, and even hearing "the pros" bad mouth it never discouraged me from upholding that Duplicate was a strong card (particularly in arena). It can be situationally bad, but playing smart can usually net you a huge benefit with it.

The latest video from Kripparian shows his reversal of opinion on Duplicate with an example of a perfect situation for it.