Is Mana Drain really a worthwhile engine card to have in the format? Why not restrict it?

As I said it was a very rough list. It seemed like a good replacement for all the Brainstorm and Ponder effects lost but the loss of the 2nd black land drop on turn 2 is a pain. Sensei's Divining Top may be a better choice, this also combos more effectively with topdeck tutors after going off.

It was still a very rough list, I'd agree with adding more Chrome Mox and Cabal Ritual to ensure you hit the black and blue mana needed. It might also work better to run 2 Tendrils so fewer cards are needed to draw into Tendrils on average. This deck is much harder to make well in Vintage than in Legacy IMO, losing full access to Mystical Tutor, Ponder and Brainstorm hurts (and convinces me that Wizards were correct to restrict both Brainstorm and Ponder). I disagree with what a lot of you are saying about top deck tutors however, once you've done off you'd generally need only 1 tutor and one draw to get Tendrils. You'll usually draw into that from Ad Nauseum.

It's instant, has a lower CC and draws 1.25 times as many cards, why would you run Yawgmoth's Bargain over one?

Webster: that's true but you will draw draw from Ad Nauseum as well so your top deck tutors are still useful. If anything I'd probably run all 4 and Yawgmoth's Bargain, I just started off on the side of lowest average CC.

An average CC of 0.8 when going off makes Ad Nauseum comparable with Yawgmoth's Bargain.

Baghdad Nauseum

        4 Polluted Delta
        3 Flooded Strand
        1 Island
        1 Swamp
        2 Underground Sea
        1 Tolarian Academy
        4 Bazaar of Baghdad
        1 Sol Ring
        1 Black Lotus
        1 Mox Pearl
        1 Mox Ruby
        1 Mox Sapphire
        1 Mox Jet
        1 Mox Emerald
        1 Mana Crypt
        1 Lotus Petal
        1 Mana Vault
        1 Lion's Eye Diamond
        2 Chrome Mox
        4 Pact of Negation
        1 Chain of Vapor
        1 Brainstorm
        1 Ponder
        1 Ancestral Recall
        1 Mystical Tutor
        1 Vampiric Tutor
        1 Imperial Seal
        4 Dark Ritual
        4 Duress
        3 Thoughtseize
        1 Hurkyl's Recall
        1 Merchant Scroll
        1 Demonic Tutor
        1 Yawgmoth's Will
        1 Tendrils of Agony
        4 Ad Nauseum

You only need one Tendrils as you will find draw and a tutor as the low average CC lets you draw plenty from Ad Nauseum. 11 disruption and 2 bounce means the deck's reasonably equipped to protect itself.

I'm a little surprised at the negative reaction toward the card, people are way too partisan between 'omg junk' and then assuming that anyone who doesn't dismiss it thinks it's the best thing since sliced bread. It's a less good Yawgmoth's Bargain so is surely worth a look. The legacy disruption that people tend to choose to go with it seems quite promising - 4 Duress and 4 Pact of Negation, the Pacts replacing Force of Will which obviously doesn't play well with Ad Nauseum. Run 2 or 3 Ad Nauseum along with Necropotence, Mind's Desire and Yawgmoth's Bargain and Mana Drain. Mind's Desire/Yawgmoth's Bargain and Ad Nauseum all fit into a similar strategy and curve. Another thing worth considering might be Intuition as a tutor as it could be used to strip your deck of the expensive cards while powering up Cabal Ritual, I'd certainly choose this over Grim Tutor which fights the deck's need for life as a resource. Thoughtseize also seems suboptimal as you need the life resources. Both Chrome Mox and Mox Diamond are worth considering although one Mox Diamond is probably the limit.

Arcane Denial would seem like a natural fit with Tezzeret.

Smmenen - are you really happy with the restriction of Brainstorm? I get the sense that you're agreeing with the restriction in your head and to take a moderate position in disagreeing with the changes over all while not agreeing in your heart, sorry I can't really put it better than that. As the Brainstorm restriction doesn't seem to do the slightest thing to the dominance of blue it seems pointless. Decks that run fairly smoothly are good, Brainstorm increases the choices available and the likely-hood that players can find answers so I think rewards skill. It seems strange to feel so determined to shake the format up when it seemed to be doing so well.

Would it not be a good idea to gather a brief version of the errata discussions in a sticky thread, that would help in keeping track of the errata debate cards and in providing a clear link for Wizards?

If they deal with Dark Confidant you're both down 1 card, if they can't or you can protect it the game very quickly runs away in your favour, it's really worth testing. Mongoose I'd agree the untargetability is very nice, Grim Lavamancer on the other hand helps break Tarmogoyf deadlocks.

What do you think of a black splash and Dark Confidant instead of Werebear? The werebears always seem weak and slow to me, I'v even replaced the Mongooses with Grim Lavamancers (this is fine with Tarmogoyf) due to the slowness of threshold.

Congratulations, nice to see IGG doing well and so unlike certain other Storm combo decks.

I think he's wrapped himself up in mindgame knots - if he runs one Daze and the opponent attempts to play around it then he's getting ahead but if you're never actually Dazing people will not play around it.

I am not Apprentice and thanks for linking the articles but I've read them before and understand why Apprentice's ideas aren't so hot.

Maybe it's not the greatest idea since sliced bread, everyone starts somewhere. This attitude will kill your community. Even if there's a history behind it anyone like me from outside the community really isn't going to bother getting involved when seeing reactions like this.

I'm not a mathmo type so can't express this idea properly but an idea for next time with this format: the value of a victory or draw should be in some way related to the spread of E-value so your deck is rated by how much greater its ability to win for a given E-value is than the average of all players. Something like 6 and 3 as usual then you multiply your points by your E-value divided by the average E-value of all decks. A loss is then still worth nothing. This might drive the push to use a lot of Es down, any ideas from the more maths-types? At the moment I think E values are a little better than trying to win, we need a scoring system that creates a balanced tension between E values and winning.

Bleh I thought the format would be more based around Wasteland, storage lands and aether vial. Well done to Jacob and let's run it again with a Gods' Eye ban.

It's more along the lines of left-field 10-12 strats being vulnerable to a minimal win condition than a good high E deck. =)

I think a 17E deck could, most effective designs seem to come in at the 10-12E range and the 17E deck can beat a couple of those. 10 to 12E decks would also have won and lost to each other while the 17E picked up a reliable 6 or so per game. The less effective 14Eish decks that would be a problem for max E decks would get caught between the two extremes, beaten by the more competitive 10 to 12s and not high enough E to compensate.

It seems a pity to require all things to be castable during a goldfish, there are plenty of valid interactive cards that require targets.

A sensible rule change, I was planning on suggesting it after dominating the format. I think with this rule the tension between high-E and mid-E but competitive decks is balanced or even requires decks to try to win rather than E all over everything.

Jacob_orlove: What was the E-value of your top deck? I got to 17 E before the ban and I'd guess we were using the same card that caused the rule change.

O RLY?

Run this one again sometime. I think it might be interesting enough to establish some kind of metagame unless of course something totally broken turns up, then you can mass ban. It'd be nice to enter more than one deck since I have some differing ideas that could take advantage of the potential metagame. I may be mistaken but I don't think any of the cards listed by name needed banning.