Upon completing somewhat long quest on grinding the heck outta the gold league I have found myself with some info. Here is the idea: people can find a little quiz about gold arena stats interesting.
Anyone can participate, just post you answer/guesses for the following questions
if you have some ideas about new tasks you can post them too. I will look whether I can get some feasible info.
All questions so far are about popular and unpopular cards. This information derived from frequency of winning different cards from spins. Rare spins after four-wins-in-a-row are not included, ultra-rare Nymphs are not included (they all turn into relics), pillars/pendulums are not inluded (chance to win them from spins are much-much lower than for any other card). Please do not consider this stats as 100% correct - only God, Zanz, and database server know the truth
Name 3 most popular cards. 90 - Nova
61 - Deflagration
58 - Steal
What a surprise. All participants were absolutely right about nova (supernova) as the ultimate champion of gold league.
Name 3 most popular creature cards. 37 - Phoenix
35 - Devourer
33 - Fire Golem
Both dragonsdemesne and Brontos are quiet close (2 out of 3 hits)
Name most popular dragon and 3 equally rare dragons. 20 - Crimson dragon
14 - Black dragon,
11 - Colossal dragon
9 - Emerald dragon, Phase dragon
7 - Golden dragon, Azure dragon
5 - Bone dragon
3 - Devonian dragon
2 - Purple dragon, Stone dragon, Ice dragon
Dragonsdemesne is da best with 3 correct answers out of 4
Guess at least 10 out of top 15 popular cards. 90 - Nova
61 - Deflagration
58 - Steal
44 - Black hole
39 - Poison
38 - SoG
37 - Reverse Time, phoenix
35 - Devourer
34 - Fire bolt
33 - Immolation, Lava golem
32 - Flying weapon
30 - Sapphire charger
28 - Nightmare, Golden hourglass
Dragondemesne - 7 hits, Brontos - 7 hits. furrballdn - only 5 hits.
Name most popular and most unpopular rare card. 38 - SoG
20 - Titan
14 - Pulverizer, Eternity
13 - Druidic staff
12 - Fahrenheit
10 - Arsenic, Pharaoh
9 - SoD, Owl eye, Vampire stiletto
7 - Arctic squid, Miracle
6 - Discord
4 - SoR
3 - SoSe, Trident
2 - SoSa, SoV, Morning star
0 - SoP
furballdn - 1, Brontos - 1
Name 3 most unpopular cards. Hint: there are actually 4 winnable cards that I was unable to win. Name any three of them. 0 - Shield, antlion, Solar shield, SoP
furballdn - 1, Brontos - 1
Name most popular and most unpopular rare weapons. 20 - Titan
14 - Pulverizer, Eternity
13 - Druidic staff
12 - Fahrenheit
10 - Arsenic
9 - Owl eye, Vampire stiletto
6 - Discord
3 - Trident
2 - Morning star
Alas no correct answers. To be honest the Fahrenheit is most annoying and noticeble rare weapon with the longest games. I was not expecting Titan to be that popular but numbers don't lie.
Name the element which cards are most frequent and the element which cards are least frequent. 
291 - Fire
212 - Darkness
180 - Gravity
153 - Entropy (with 90 novas)
145 - Time
115 - Life
113 - Earth
112 - Death
91 - Air (with 32 flying weapons as the savior)
89 - Aether
74 - Light
68 - Water
furrballdn - 1 answer, Dragondemesne - 1 answer
No absolute winner, sorry guys. furrballdn gave 3 best answers, both Brontos and DD was successfull 4 times. Draw? Full stats:
90 Nova
61 Deflagration
58 Steal
44 Black hole
39 Poison
38 SoG
37 Reverse Time, phoenix
35 Devourer
34 Fire bolt
33 Immolation, Lava golem
32 Flying weapon
30 Sapphire charger
28 Nightmare, Golden hourglass
25 Graboid
22 Relic, Rain of fire
21 Momentum
20 Crimson dragon, earthquake, Titan
17 Acceleration
16 Rage potion, Ghost of the past
15 Photon, Drain life, Minor vampire
14 Bone wall, Antimatter, Pulverizer, Horned frog, Eternity, Black dragon,
13 Druidic staff
12 Hematite golem, Gnome rider, Forest scorpion, Mitosis, Fire spirit, Fahrenheit, Sanctuary
11 Colossal dragon, Cockatrice, Sundial, Fractal,
10 Arsenic, Flesh spider, Purify, Pharaoh, Dusk mantle, Nightfall,
9 Emerald dragon, Otyugh, SoD, Fire shield, Ice shield, Owl eye, Dune scorpion, Vampire stiletto, Lightning, Immortal, Phase dragon, Quintesence,
8 Chaos seed, Armagio, Forest spirit, Heal, Chrysaora, Blessing, Firefly queen, Shockwave, Parasite,
7 Gravity pull, Shrieker, Thorn carapace, Freeze, Arctic shield, Arctic squid, Steam machine, Golden dragon, Miracle, Azure dragon, Wings
6 Virus, Discord, Fallen elf, Pandemonium, Enchant artifact, Toad fish, Guardian angel, Dragonfly, Unstable gas
5 Plague, Mummy, Soul catcher, Plate armor, Pegasus, Gargoyle, Voodoo doll, Cloak, Mindgate
4 SoR, Boneyard, Deathstalker, Lycanthrope, Butterfly effect, Gravity shield, Ash eater, Crusader, Fate egg, Scarab, Liquid shadow,
3 Short sword, Hammer, SoSe, Bone dragon, Maxwell demon, Abomination, Shroedinger cat, Graviton mercenary, Graviton fire eater, Catapult, Stone skin, Rustler, Blue crawler, Trident, Nymph's tear, Reflective shield, Luciferin, Wyrm, Devonian dragon, Anubis, Precognition, Spark,
2 Short bow, SoSa, SoV, Vulture, Skull shield, Skeleton, Purple dragon, Dissipation shield, Mutation, Stone dragon, Iridium warden, Emerald shield, Ice dragon, Morning star, Thunderstorm, Déjà vu, Silence
1 Dagger, Aflatoxin, Chimera, Titanium shield, Basilisk blood, Mind flayer, Ice bolt, flooding, Holy light, Hope, Fog shield, Firefly, Sky blitz, Procrastination
0 Shield, antlion, Solar shield, SoP
When the correct answer will be given this post will be edited.
Clarifications:
a) all pillars/pendulums are out of competition ( including quantum pillars)
b) question 8 was paraphrased to make it clear
c) upped and unupped version of the card are considered to be the same
