About the brainstorm issue it's 6 months I play them and I never found something bad abuot them. Yesterday I played u/r build in local tournaments where 60 people attended at and I won games only thanks to brain.
A build like mine finished 8.

I think that fish should side cards that could used also in some other matchups, for this reason in my u/r build i side in 3 extract and 2 sigil/ensaring bride, not yet decided what it's better.
Sigil/bridge can be used against any aggro deck, bridge is better but slower.
Extract is cool against any combo decks and maybe dragon too.
For other builds i like simplify.

I'm playing fish-like decks since a long time, and actually think that the correct draw engine is 3 brainstorm 3 curiosity 3 standstill. With such configuration you can dig in your deck when you're searching for the answer you need or reshuffle back in to your library cards you don't need in that moment.
For the rest of your build i like kami in side, but how -4 cloud + flying man?
It's the same card excepts it doesn't cycle but it changes your ccs. A chalice set at 2 it can wrec you down.
Then I think you lack countermagics withou any daze or stifle. 2 misdis are good vs control but so bad vs artifact decks.
Seems too much a deck based to beat ONLY oath.

i was thinking at a wtf u/g build with a trasformational sideboard (oath) for aggro matches, even if I don't know what cards side out for them. Moreover they are a large numeber of sideboard slots.
I'm still wondering how to beat artifact decks.

Thanks for all replies. I can think from your posts that no one shares my idea, so there's no reason to keep this topic going on, and letting people just say: play flying men.
To moderators. can be closed

I completely agree with wuaffiliate. Moreover I actually don't bielive that a 3rd color splash is what fish needs.
I was thinking cutting 1 daz e 1 stifle for 2 coral fighters. They' r not evasive at all but I think they can win games ad has the perfetc cc.

The problem with stifle is that sometimes you have to decide wether to play manta rider or just save your mana to stifle your opponent fetch and maybe sometimes losing tempo.

LoA by me it's a good card because has iimediately effect in play and without merfolk is still a decent blocker.

That's partially true, but this deck is far more faster than gay/r and pumping 2 merfolks implies having dubled p/t of your creatures.
Moreover you get the chance to win against some decks also in bad situations like angainst a roar of the wurm or an atog. the moerfolk number in the same gay fish always used, I only replaced the too slow Thief with Razorfin Hunter.
My really urgent question is: is correct going in mana denial direction with LoAt pumping philosophy?

First of all I have to excuse myself for my poor english, i hope than it will be enough clear and that discussing with you would improve it.
Here in Italy an high competitive tournament metagame is developing, together with realy good palyers, as Gencon results shows.
A lot of different full powered decks fights everey sunday; but in this tournament there are also a lot of unpowered decks that tend to establish a metagame in which more or less 40% decks are aggro, 40% are control 20% combo.
The most common archetypes are HS 4CC Goblin Sligh, Fish, Madness (RG, URG), Zoo, TPS Dragon, WS Prison decks, and from last tournaments, also Affinity and WS Slaver.
It's a very fast metagame.

I have alway been a fish player since gay fish was a merfolk based build and alway tried to fit this deck to my metagame with various splash and finally I obviuovsly merged to a quite common gay/r list. Some cards are personal choiches as always in this deck.
Now I was thinking to return to a merfolk build because I bielieve that it has a faster clock. The need for red for removal implies a red splash making possibly the use of pretty razorfin hunter.

This is the list i was thinking at

4 manta riders
4 cloud of faeries
4 razorfin hunter
3 lord of atlantis
4 standstill
4 curiosity
1 ancestral recall
1 time walk
2 fire/ice
4 fow
3 daze
3 stifle
3 null rod
1 mox sapphire
4 mishra's factory
4 blue fetchlands
4 volcanic island
4 island
1 strip mine
4 wasteland.

Comments
Good things
This deck has a faster clock;thanks to lord and merfolks. The use of razorfin hunters implies to be less intesive on red mana sources, and this to fact helps a lot also in the mirror match which is now quite possibily in a tournament.
It's also very good against control which with 4CC is spreading here.
Morevover f/i gives istant removal vs noisy creatures, expecially goblin welder and is never completely useless. (you can alway cylce it).
Denial base is quite good even if i'm wondering if misdirection would be good. ( in some matchups it's completely unuseful).

Bad ones
Lack of spiketail hatchling to complete mana denial.
Lack of grim lavamancer which sometimes it far more better than razorfin hunter.
Sometimes having the need for double specific casting cost may be a problem: and this is a problem which involves 7 critters.

Firts matches have been pretty good.
I was just wondering if it's correct going in this direction together with the denial base supposed by gay/r or if I just have to establish winning condition as in old fish builds which used to be less intesive on mana denial.
This fact for example would men cutting some dazes and stifle for a lot o cool stuff like disrupt, more creatures, merchant scroll. all cards that was played once in gay fish (with merfolks).

In the end my actual sideboard for this deck
3 beb
3 reb
3 sigil of sleep
3 tormod crypt
2 rack and ruin
1 hurky'll's recall.

I'd like to hear some thought about this deck expecially on what concern mana denial strategy and its concequences in the deckilist.