Noob question : Is there any efficient way for us to determine whether a team will expect a counter-deck or not?
Hm. Well not really; PvP is all about trying to predict what deck your opponent will use.
But strong decks stack the odds in your favor.
So don't go with a completely outrageous strategy, but don't do something predictable every time.
Perhaps you could pick the 2nd best deck against your opponent? If they counter the 1st best deck you'll be fine; if they don't, you'll probably be fine.
I'll use my match as an example. Firestall has a good winrate against most death decks, but they will expect that. Last war, death used earthquake decks against light. So I'll be using a deck that is effective against death but is not super-vulnerable to earthquake (like firestall would be).
Here's what I have in mind. I've tested this against death's first two decks they used against us last war and it's doing well. I'll post the full results when I'm done testing.
562 562 5ld 5ld 5lf 5lf 5lf 5lf 5lf 5lf 5mq 5mq 5mq 5mq 5mq 5mq 5mq 5mq 5mq 5mq 5mq 5mq 5mq 5mq 745 745 745 745 745 745
Chargers are great against bonewall, which they will likely pack. Blessing complements overdrive. The shields slow them down a little and help against earthquake. Simple, but effective. Note that I upgraded the cards I need upped and only the cards I need upped.