I'm actually quite suprised that you baorded out your counter magic for hate cards and REBs against Fish. How did that work out for you during tournament play? Was there any situation that you felt that the addtional counter magic of FoW and Drain were to be useful? I asking this because I feel that 4 REBs, on paper, seems very little to protect your own business (Gifts Ungiven, Merchant Scroll) and hate cards (Seasinger, Massacre, Pyroclasm).
The reason for this is that you have so many threats for the Fish player to stop that they shouln't need protecting. If they counter your business your removal takes out their creatures leaving them with no clock. If they counter your removal your business just draws you into more gas. Other than mana and creature disruption, both of which are much weaker against you post-board, fish has only 4 Fows and minimal tutoring/draw to get them. That isn't going to be enough to stop everthing you throw at them, plus 4 REB. Drain and Force aren't as useful for protecting your spells because you often either don't have the mana to leave open for Drain, or you don't want to pitch a card to Fow because you could just cast another threat anyways. The only card that I want to be SURE of resolving when I cast it is Yawgmoth's Will, and by the time I cast that Fish has probably already lost anyways (and even if you mess up and it gets countered, you still have Recoup.)
Actually, I've seen people siding out FoW/MisDs for REBs against Fish and variants and keeping their Drains in. The flip side to that is that most Fish players are adapt in playing around Mana Drains, imho.
@Gandalf,
You can actually side out Tinker+DSC for 2/3 Seasingers, using the Seasingers/Old man/Threads as kill conditions itself as it steals your opponent creatures. Talk about the tempo they will lose while you set up your play. I felt that leaving in the tutors are a must since setting up the ToA win condition is much more elegant than Tinker/DSC since Burning Wish is not in the MD.
As most of you might know, MDG is a very complicated deck to play. At times, one will get stuck with the Tutorful hand with Gifts and having so many insane plays. With such complexity, how would MDG play out against the mirrors and other drain.decs? Would it be control or aggro? Its confusing sometimes with ToA main, as it makes the deck much much faster that most players tend to just go for the kill.
Correct about the playing around drain part; if the Fish player is stupid enough to have you drain one of their threats they suck and are going to lose anyways. It's far better to have them play around Drain when you don't have it in (or even not be sure whether to play around Drain or not)
Good point about possibly stealing their creatures as a win condition; I hadn't really though of those cards outside of their disruption in slowing the Fish player down and acting as removal of a sort.
The tutors are good at the time when you are going for the kill, but I find often limited at other times when I would rather have another card that does something rather than costing me draw and tempo. Individual games vary, but I find the proper role for Gifts against Fish is Control post-board. Fish is designed to punish you for trying to goldfish them as you would an aggro deck with no disruption; they want to abuse one of Gifts' attributes that can be seen either as a strength or a weakness; the fact that it does't interact with the board. Once you actually have things that interact with them, their task becomes much more difficult because like I said, they have to deal with both your answers and your threats, and it is simply too much for them.
The proper role can sometimes be difficult to determine. It often changes not only with the matchup, but, as you stated, with your particular hand as well. I often try to play the control role in most matchups until I see the point where I am sure I can go for the win, and then do it, but this isn't possible in all matchups (for example, against Ichorid, you have to goldfish them as quickly as possible while they are disruptiong you with Leyline/Chalice/Therapy/Unmask, etc as well as having a very fast clock. Most of your control elements (ie, counters) do almost nothing against them as well). The other thing that can make it difficult to determine is that sometimes when you have an advantage you can win with any number of plays assuming either role, so it may not be clear even in hindsight which was optimal or not. The time limit factor for decisions in tournements can also be problematic. You have to have tested enough that you can make not only the right decision, but make them quickly as well.