How do you know which decks are most commonly used, unless you look at the server-side stats?
Deck Helpers, Staff members, make the determination based on everything that's posted on the forum and in chat.
I think there are just recommended decks, not only the most used.
They are the most used and therefore recommended.
I see, so I shouldn't have posted the decks I've posted in the community since that's my recommended decks and not the community ones (except for Cocky HB Killer, in which case my opinion and the community ones are the same).
Anyway, I did a little testing with 3 well-known mostly (or fully) unupped & rareless decks against the Gold & Platinum leagues and here are the results (I post it here because I think you will be interested):
{1} Very Good Unupped HB Farmer: http://elementscommunity.org/forum/index.php/topic,36282.0.html*Games Versus Gold: 30
-Games Won: 5
-Games Lost: 25
-Elemental Masteries: 1
-Lucky Spins: 0
-Winning Percentage: 16.67 %
*Games Versus Platinum: 30
-Games Won: 4
-Games Lost: 26
-Elemental Masteries: 0
-Lucky Spins: 0
-Winning Percentage: 13.33 %
{2} Fastest Unupped Mono AI3 Farmer: http://elementscommunity.org/forum/index.php/topic,10503.0.html*Games Versus Gold: 30
-Games Won: 5
-Games Lost: 25
-Elemental Masteries: 1
-Lucky Spins: 0
-Winning Percentage: 16.67 %
*Games Versus Platinum: 30
-Games Won: 2
-Games Lost: 28
-Elemental Masteries: 1
-Lucky Spins: 0
-Winning Percentage: 6.67 %
{3} My RoL/Hope Deck (Mostly Unupped): http://elementscommunity.org/forum/index.php/topic,14533.0.html*Games Versus Gold: 30
-Games Won: 15
-Games Lost: 15
-Elemental Masteries: 0
-Lucky Spins: 3
-Winning Percentage: 50.00 %
*Games Versus Platinum: 30
-Games Won: 6
-Games Lost: 24
-Elemental Masteries: 3
-Lucky Spins: 2
-Winning Percentage: 20.00 %
Personally, I have learnt two great things from these tests:
1st} I've learned that a decent unupped & rareless deck can easily reach a 15% winning rate in Gold/Plat league, however reaching or exceeding 20% is a difficult task (like Calindu said). So, in my opinion, an unupped rareless deck if ever succeeds in bypassing 20% winning percentage after a serious playtesting of 100 games in Gold/Plat league, then it can be considered a "farmer" of that legue.
2nd} The mostly unupped Rol/Hope deck is not only a good FG killer but also a pretty decent Gold League farmer with very good winning percentage for a deck with just 6 upped cards and 3 rare weapons.