They have these completely abysmal blood control death knight decks with 60, 70% win rates and its just a junk deck. Three quarters of the deck is above 6 mana and its filled with board clears. That is a disasterful deck good against ONE archetype, arguably even ONE DECK, beast hunter
Then the frost dk variant is like 44% win rate whereas if you played them side by side you’ll notice something fishy where frost performs better like way better.
I have it on good authority that some of these stats are inflated (ie they close the tracker program before conceding a game to keep a perfect/high record)