Many thanks for doing this analysis. I've always been interested in game theory and the modern vintage metagame is a great case study!
I actually think it's entirely possible that vintage is a 'one deck format'. There are many ,many reasons for this, here are just a few off the top of my head:
We can't assume that everyone has perfect information. With the advent of MODO vintage and analyses like this one, we are trending towards more information, but it is far from perfect. Some players still show up with outdated decks. And I'd argue most don't know the 'win percentage' of archetype A vs. Archetype B.
We can't assume everyone is a rational player, whose sole goal is to win. People have deck and play style preferences that push them towards sub-optimal strategies. Some play to have fun, so winning is secondary.
Another hypothesis is it is much easier to 'screw up' playing blue than shops, i.e. blue decks have a larger decision tree and therefore also more opportunities to make mistakes. Given that most vintage players are fairly casual and are not on the pro tour/grand prix/scg tour grind, they are more likely to make mistakes when on a blue deck.
I don't know if there's a solution to this problem outside of more restrictions. The power of shops since printing of lock pieces started in Mirridon has always been that even if you packed a metric ton of hate, you still lose if you can't cast any of them. That problem still exists and will continue to exist as long as there are turn 1 spheres powered out by workshops. We know workshops are not going anywhere, so that leaves thorn or sphere, both of which seem way to underpowered to be restricted.
P.S. Frank Karsten wrote an excellent article examining what makes a good constructed format using game theory, highly recommend everyone to read!: https://www.channelfireball.com/articles/what-can-game-theory-tell-us-will-make-a-good-constructed-format/
In U vs U, you need to outdraw your opponent, because barring a few threats, most can be answered in some form or another.
Card Draw: From experience, a key card in mentor vs mentor has been sylvan library, but it can apply to any other slow/controlling U vs. U match-ups. JVP can be plowed and pyroblasted, but sylvan library can only be answered with FOW mainboard.
Answer: Pyroblast is an obv removal spell for the mirror, but abrupt decay also seems pretty great as a removal spell. It deals with the most common win conditions: mentor, JVP, dack, leovold, vault/key, oath. With gush now gone, it's a better answer to mentor than before.
4: Threat: Mentor is still a great threat, non-blue 4 cc planeswalkers like Nahiri also seem well positioned. Leovold is great since it stops card draw and gets you a 2 for 1 almost all the time. Mishra factory is also secretly very very good. It threatens planeswalkers, and gets in for dmg when there's a mana drain staring contest.
Shops is obviously not going anywhere, because even decks designed to 'beat' shops can't do so consistently on the draw if they don't get to cast their spells. Oath was traditionally great vs. shops but now with fleetwheel cruiser (+factory activating it) the matchup is much better for shops. And walking ballista can now deal the final points of damage without giving oath another turn.
Landstill is likely to next best option to combat shops, but again i think anyone claiming a great shops matchup is vastly overstating their win %. Moreover, before there were eldrazis, it was reasonable to sideboard 6-7 artifact hate cards and call it a day, but now blue decks have to also contend with the tentacle menace.
Long story short, thorn decks will continue to be dominant, but we will see a wider range of blue decks, and combo still sucks =/.
I guess the cat is out of the bag at this point =).
Definitely credit to BK for coming up with adding sylvan library to mentor. Just to add to Rich's experience with the deck, I'm also at something like 23-5 in real life tournaments with this deck, and have top 4'd 4 out of the last 5 tournaments I played in.
One question I have for Rich is have you tested 3x sylvan library?
I've won almost every game where I have a turn 1 sylvan - redundant copies are near useless, but we do have dack and jace to get rid of them as needed. Now that people know how good it is, they are also more likely to FOW the first copy. Lastly, you can always not draw additional sylvans with proper use of fetchlands to shuffle them away.
@Topical_Island I completely agree with your take on Yawg will's role in the deck. To broaden the topic, I would really love a Frank Karsten-type of analysis on the percentage of time you need to have 'something else' to win once you have oathed into Griselbrand, because there are a few other cards I'm not fond of in the deck: the vault key combo and memory's journey. They are all do nothings that I hate to see in my opening hand, similar to yawg will, except way worse, because they are also awful top decks.
To fix this issue, I came up with a list that replaces the vault key combo with an additional S&T and omniscience. Then I replaced 1 griselbrand with 1 emrakul. S&T + omniscience both pitch to force of will, and both have applications pre-oath and post oath. Pre-oath, omniscience is another S&T target, S&T is another enabler for griselbrand/emrakul/omniscience. Post oath, it functions similar to vault key as an "instant kill" via show&tell + omniscience + emrakul.
If the above idea sounds familiar, it's because Montolio (Andy) won the recent power 9 challenge with my list. We tested the deck a few times and felt that the only weakness is oathing up emrakul when you really need griselbrand - e.g. when playing against storm, when facing a horde of lethal mentor tokens etc. Another issue is if you oath the omniscience into the graveyard, then you don't have a instant win anymore unless you play the awful memory's journey. But in most games, oathing into griselbrand then emrakul and vice versa on consecutively turns generally seals the deal.
Thanks for writing up this primer on Fenton Oath! Like many aspects of Vintage, there's a 'wild west' feel to deck/archetype theory and primers like these really help establish a baseline for each archetype, similar to the DTB and established deck section for Legacy at the mtgthesource.
I love this deck and exclusively played this deck for a full year in paper tournaments (NE weekly tournaments, NYSE, Champs etc.). I know nothing about online so here are my 2 cents based on paper games only:
LSV actually played a similar list at vintage champs last year, he was 7-1 before having to drop to catch a flight. So ignore Pikula, oath is real deck and can be a great choice for some metagames.
This is not the best JTMS deck for sure, but like you alluded to, the 'brainstorm' effect is absolutely insane and necessary for this deck. I've been extremely happy casting JTMS while giving my opp a token, because I still get 3 brainstorms out of it before it dies, AND Jace can always tick up. JTMS is also by far the best card in the mirror, so I'd be very reluctant to not play at least 1, usually 2, and have been happy with it.
On a note re: the mirror - Yes traditionally you sideboard out 3 oath, and 2 show and tell. You win the following way: After establishing orchard dominance, tutor for your single oath, hardcasting griselbrand eventually or stick a JTMS. If you play vault key, that is another way to win obviously.
My main issue with the deck has to do with consistency. There are an upward of 6 cards (3 grisel, vault/key/memory's journey) that do almost nothing on their own in the deck, and having any of them them in your opening hand (50% of the time by my estimate) feels bad. You can get lucky and even spike a tournament or 2 with great draws, but eventually the variance will catch up to you.
The other issue is containment priest. While abrupt decay is a great answer, mentor just does not give you enough time to find the decay due to how quick of a clock it is.
While winning game 1 is easy, 2 and 3 becomes nightmares IF your opp is well prepared. When ppl are unprepared against oath they get crushed.
Completely anecdotal, but fun anyways: Last weekend, I played against Greg Fenton and he is on the play with the following draw: lotus, recall, oath x2, orchard, land, flusterstorm. I beat that god draw with a turn 1 aegis of gods plus double force of will hand. If the game dragged on longer, he might have found an abrupt decay, but because my deck has more velocity, I was able to find a containment priest before that happened and seal the game completely while he just sat there playing draw go for awhile.
Take out all the bolts (lodestone is gone) and sideboard the sudden shock. You are underpowered vs. mentor, so having a combo element is likely the best approach, - you can still kill them out of nowhere even if mentor has board dominance. I like the gush-fastbond package you got there. JVP is great in a fastbond gush deck, as it allows you to flashback gush when you're comboing off. empty seems sweet, though maybe tendril might just be better? Not sure. I can also see not playing those cards, because I hate dead cards that don't do anything on their own (and space is REALLY tight in this list) Here's my list:
4 young pyromancer
2 jace, vyrn's prodigy
4 gitaxian probe
1 ancestral recall
4 force of will
4 mental misstep
1 time walk
1 dack fayden
2 cabal therapy
1 yawgmoths will
1 demonic tutor
1 vampiric tutor
1 merchant scroll
1 treasure cruise
1 dig through time
1 black lotus
1 mox jet
1 mox ruby
1 mox sapphire
4 scalding tarn
3 flooded strand
2 volcanic island
2 underground sea
1 tropical island
1 library of alexandria
2 ingot chewer (shops / storm for defense grid)
3 ancient grudge (shops)
1 hurkyl's recall (shops)
2 sudden shock (mentor)
2 abrupt decay (mentor / oath)
1 Ravenous Trap (dredge)
2 Yixid Jailer (dredge)
1 Gradigger's Cage (dredge / oath)
1 Cabal Therapy (storm / oath)
In terms of matchups, you should destroy storm and other random combo decks, have a pretty even matchup vs. mentor (assuming you're boarding in 2-3 sudden shocks vs. mentor) and probably get pwned by workshop so definitely have 2-3 chewers and 3 ancient grudges and at least 1 hurkyl in the sb (can be tutored).