On most points, I definitly agree with Necrologia.
I dislike running the fourth color, because the gains are pretty marginal now that Thoughtseize exists to take REB's spot in the SB, while the less stable manabase makes your hardest matchup (shops) worse. A metagame with tons of Goblins and few Workshops would be the exception.
On winconditions: again EtW is not worth the splash imo but great once you do run red. DSC doesn't have enough artifacts to Tinker out and Meloku is simply to expensive and outclassed by other options.
Dryad is solid and the only creature that isn't actually bad in any matchup as long as she's dropped early, but neither is the best in any match if cast after turn 2 (SuperLong aside). She's pretty much your allround dude. It also makes her the only creature not necessary in general.
Tarmogoyf on the other hand is pretty bad against anything not running Workshops or mass-creatures (3/4s suck so much in the mirror!). It is your best option against shop though (against ShopAggro to buy time to develop mana out of Sphere-range, against Stax to come down early and finish it before the board gets eaten).
Psychatog (with a maindeck Berserk) gives the deck a second fast combo-kill not reliant on having a solid life-total or finding Fastbond. It's also the best lategame creature the deck has, besting everything in combat.
The creature-base I'd run in the end is dependant on the metagame, but should probably look something like this
2-3 Tarmogoyf OR Dryad (with 2-3 Tarmogoyf SB), possibly even a mix if SB-space is low
2-3 Psychatog (MD Berserk)
So 5-6 creatures total, the more Shops the more creatures (and the more likely Goofy MD).
GAT should run Mana Drain and at least a single MisD is usually needed, too. Even with Ponder weakening it, a solid hardcounter aside from FoW is needed. It also helps immensely vs Stax. I think 2 Drains is the right number, as you definitly can't support four without being hampered in casting Ponders. A single Drain may be the correct option in certain metagames. MisD's value on the other hand is directly proportional to the amount of Merchant Scrolls floating around. If half the field is playing 3-4 Scrolls 2 or more MisD are pretty much mandatory imo, in a more balanced metagame one is fine to have the random fifth pitch-counter for the counterwars.
As for Thoughtseize, I believe Duress is strictly better in the deck as you don't support the lifeloss well against many decks. Four Duress effects are mandatory in the deck, imo, and six is the maximum number I would run. As mentioned before, if you're not running red, Thoughtseize is your go-to SB card (After board you might go up to 7 Duress' even, but I'd say never more).
Cunning Wish, ime, sucks. The only thing it does well is pitch to FoW. It is slow and clutters your SB or is really really bad if you don't need the Berserk atm. Your only MD answers should be a Echoing Truth and your creatures (plus likely a F/I if you're running red).
I would never ever cut the MD Truth just because I have a Wish, btw, like zeus suggests. Yes, sometimes it's the worst card you can draw, but I've been saved way to many times by the speed of Scroll-Truth to ever consider slowing it down by three mana. It's conceding games to bad players with good luck in drawing Tinker, EtW or Oath to do so.
Berserk MD on the other hand is just great, giving you a second speedy combo-kill that is cheaply accessible (mad important vs Shopp-aggro). I should note that I believe running Mystical MD is an error if you don't have the Berserk. Mystical is actually pretty bad in GAT and only the fact that you suddenly get four additional ways to go Tog + Berserk (think I'm gonna call this Tetris from now on) on the opponent with Tog makes it worth it.
The approach really depends on the matchup and your draw. Against most control-decks, FAST combo and Fish-like decks, I prefer going the slow route, outdrawing them, then dropping GushBond, Will or Tetris and ending it in one fell swoop. Against Oath, my prefered way to win is actually beating them to death with Spirits
Against Shops, you want to be fast and just go for a quick Goyf-kill or Tetris them. Post SB Flux/Predator can often stand in for an actual kill.
Against control-combo like SuperLong, your role is most difficult to chose, as you have to be aggressive and defensive at the same time. This is the matchup where changing roles on the fly is most important. You have to sometimes be extremely disruptive (going as far as Vamping for Duress instead of Ancestral) and sometimes very aggressive (this is actually the matchup where Dryad is at its best as it is the only thing that kills fast even if you don't devote any resources to it whatsoever. And you will regularly not really have time to stop hitting disruption to get draw to refuel. Her only weakness here is not being blue, which is sadly huge.)
As for the SB, Jailer + Needle is far better than Leylines vs Ichorid (and Needle also helps the Shop-matchup). I'd play Leyline only if I expected quite some flash in addition. simply having six Duress postboard already is quite good against Flash so if I'm likely to face Flash only once, I'd stay with Jailer. 3 + 3 is what you need to actually make the matchup favorable enough post SB to turn it around generally, ime. If Ichorid is very low (and I mean VERY because without enough hate this is far worse than Stax), I might cut a needle, followed by a Jailer. I wouldn't go below four cards if I'm not 100% sure that there is not a single person playing Ichorid.
2+ Oxidize are mandatory, imo, as are 2 bombs be it Predator, Flux or something else (usually Artifact Mutation, Grudge etc). An additional land is pretty good for this matchup, too.
If you don't have them MD, Goofy is pretty much a given to shore up both aggro and Shops.
I also think you definitly want 2 additional Thoughtseize (assuming 4 Duress MD) or REB and possibly a MisD (if you run only onbe MD as I do).
So the base SB for me is
2 Oxidize
2 Predator/Flux
3 Jailer
2 Needle
2 Thoughtseize/REB
leaving four slots up for other factors (MD configuration, expected metagame, etc)
Well, those are my views on GAT, hope they help somone out there.
