Here is a thought experiment. How would you design a deck for Vintage without a side board?

I know some will say this is dumb, and it kind of is. Vintage has hyper-efficient decks that can win turn one. If you look at Vintage 70% of the meta-game is 4 decks

20% - Shops
20% - Paradoxical Outcome
20% - Xerox
10% - Dredge

Survival is only about 5% of the meta based on what have seen but I could be wrong so feel free to flame me out.

Moving on, if Vintage were a best of one format most people would play Dredge or Storm, maybe Paradoxical Outcome. I think that is too dumb to discuss. But a best of 3 where game 2 loser goes first and game 3 is a coin flip on who goes first, like they are doing for the Mythic Champs is interesting.

How would you build a deck for such a arch-type? Is Vintage even fun in a design like this?

I think I would play something like @brianpk80 's grixis control list. A good deck, that manage to work with a little bit of hate for everything in the maindeck.

Trying to beat the field is hard. I think a big blue deck might be able to do it, maybe shops. If you try to have a better game against 3/4 of the field and eat the losses you might do better. My picks would be big blue or shops for the whole field, assuming a lot of MD dredge hate out there.

Definitely 2 card Monte, it runs Leyline, and REB, and Welder maindeck. This wrecks the "meta" without a sb, and only gets "wrecked" by something main decking multiple Stony/Rods.

I would go into this field assuming a lot of the sideborad hate has been main decked. Otherwise take a deck that usually losses to sideboards and has a high game one win rate and play that. (dregde, shops, PO)

One thing that can probably give you some insight (if this kind of data becomes available to us) is the metagame in the best of one standard format of MTGArena. Those are very different games, vintage and standard, but maybe the way decks are build in that format can give you some insight to this situation as those are games with no sideboard.

Or maybe storm. I don't know how are the % of this, but Cyrus beat dredge in the VSL with no GY hate and he told that was the plan, to prepare to other matchups and try to race dredge. Maybe pack some extra hurkyls' to beat shops on the draw or something like that? The problem would be more hurkyls means slower wins, which can make it worse against dredge. But I'm no storm pilot to really assure you anything I'm saying. All I know is that vintage storm always seemed pretty strong everytime I played against it.

@gutocmtt That was the idea behind the thread. A lot of decks are designed to be efficient but have weaknesses that can be exploited on sideboards.

In a meta with no sideboard, your deck is less efficient and includes the hate for other decks. Decks that do not need to do this just race the meta.

I have been taking a step back from the meta to find something more interesting and this concept takes me back to the old decks when people played Keeper, Grow-a-tog, Academy, and Long. These decks all played wish cards and basically added very few cards from their sideboards between matches.

I'm not trying to go back, but the concept has phased out of the modern meta. I think building a deck that is either super efficient and fast or is very resistant to hate is our meta now. There are weaknesses here that can be exploited and should be exploited.