As a two-off it does not happen that often. You should already know when you normally draw one of your two Goyfs. It is the same here: That is in the end game state. That is why we do not need 4 Shamans to support TNN in the midrange beater list. Turn 2 TNN is perhaps the case in 4-5% of the tested matches. So TNN is only good for bUrg as a sideboard card versus control/midrange as "Mongoose number 5" that can stall games/kill planeswalkers thanks to evasion or as a main deck card in a meta that eats tempo decks for breakfast. But I hope the latter kind of meta will not exist long enough. Combo decks will clear the fields so that the meta will become balanced even in regions where midrange decks reign supreme. Then we can just play with the stock list in every part of the world ;-).

