Pro Tour Eldritch Moon has pretty clearly demonstrated the power of cheap card quality effects. For the first time in Magic history green has access to more good card quality effects of this nature than blue does in standard. Shock horror, all the best decks are green and all have a boat load of these card quality spells. We have the good cube cards Grapple with the Past, Traverse the Ulvenwald and Oath of Nissa and we also have the more awkward but interesting Vessel of Narcency and Gather the Pack doing a fair bit of work in standard. It would seem the only decks not playing a significant number of these cards are the Collected Company decks which rely on having a very high percentage of their decks as creatures. Collected Company is somewhat a card quality effect on top of its other perks so all in all green has the good cards of this nature and consequently is dominating standard.
Green may well deserve the title "the new blue" in standard where most decks are what I consider midrange affairs, the format is slower and less powerful and only really Anticipate exists in blue as a card quality spell. Standard is highly driven by creatures and these green cards are at their best when creatures are the main source of action you are looking for. The cube is a different story, all the older blue card quality cards are still in the format. Green may have jumped from having basically just Sylvan Library to having a decent spread of effects of this kind but it is still a third of what blue has at best. Further to that the blue stuff in cube is not fussy about card types. Blue card quality can provide quality regardless of your deck makeup while green card quality is a little more restricted in where you can play it. A classic example is the blue green infinite turn style deck where most of your action is instant or sorcery type. In such decks Sylvan Scrying is probably going to be better than any of these cards as all you will be getting is lands, and by that logic some kind of Rampant Growth likely better still. While these green card quality effects may not be great in certain combo and control cube decks it by no means makes them too narrow or too weak. The cards are very well suited to most green decks as the makeup of green is so creature heavy. There are some creature based combo decks which these will be pretty interesting additions to. Another reason these cards hold their own in cube despite being narrower than the blue alternatives they typically pack a little more punch for the mana. On a one or two mana card a little more punch goes a really long way!
Green is still green in the cube and blue is still blue. Green just got way better recently because it gained access to all these potentent card quality cards that help it to do what it does better. Green often curves steep and hard but now it can do it smoothly and consistently too. In a deck which is all mana and threats the difference between a good draw and a bad one is huge and these cards sort that out so well. It is all so new and so sudden I have yet to fully understand how to best be using these various cards despite playing with them plenty and finding them to be generally good.
That is sort of all I have to say specifically in relation to the title however I intend to have a little look at each of the cards individually. If you're not into card review and analysis then the rest of this in not for you! Chronologically ordered we start with Gather the Pack. While I tested out Gather the Pack out in the cube it never really worked out too well. The card is good but the things you need to make it good are awkward to achieve in cube. It was too hard to build a deck that wanted card quality/advantage for two mana that also had a really high creature count (40%+) while being able to achieve spell mastery. Without the ability to gain spell mastery Gather the Pack isn't all that exciting as it is too narrow. It just finds creatures and nothing else so despite digging five deep and having the ability to gain a cheap two for one it didn't see close to enough play.
That historically has been the trouble with the green card quality effects. There are lots of them but too many of them only found one kind of thing which then wasn't really sufficient quality for your mana. You basically need card quality to be able to find land or action. Card quality smooths draws by reducing the risk of both floods and screws. You have lands or spells as a better option than card quality if you only need to reduce your odds on one of screw or flood but no deck is really immune to either hence the value of good card quality. It doesn't matter so much what that action is provided you can play enough of it but you do need both land and action options on your card. Ancient Stirrings was the first that kind of found you either but it is incredibly restricting on what action you can find so it only gets played in a select few decks. Then along came Seek the Wilds, a card I dubbed the green Impulse. It was the first of many green cards like this that found both land and action. I was excited about playing it but found it relatively rarely getting deck slots. I can't really say why it wasn't cutting it at the time, perhaps we were not ready to use green in that way yet! While it mimics Impulse it is weaker in every way and offers nothing else. Later green card quality effects started to offer bonus perks on top of just card qaulity. I hope Seek will find its way back into the cube in some manner but certainly for now it is rather overshadowed by the more recent additions.
Oath of Nissa was our next green gift. Comparable to Seek but effectively more in all areas. Now we get to find planeswalkers as well as dorks broadening our scope for action. We also only have to pay half the price for three quarters of the dig. Oath of Nissa also does a tiny amount of work in making planeswalkers easier to cast. It has some synergy with devotion and a broad selection of other things because it is a permanent. Fundamentally Oath of Nissa is most alike in mechanism to Slight of Hand except you look at 3 rather than two. Obviously the payment for this is the type restriction. Assuming your deck is entirely targets for Oath then it is on average more powerful than Ponder, Preordain and Serum Visions leaving Slight of Hand in the dust! It is not categorically better, even with all tergets there are situations each of the others would outperform the Oath but baseline Oath gives you the "most" card quality. This scale diminishes to unplayable as you reduce the target count in your deck so Oath is interesting in that regard too. Oath does a lot of work for the mana, it gives you information and then choices all while digging pretty deep.
Traverse was next up and it is really quite special. Lay of the Land was playable and Traverse scales quite significantly better! Most of the time just Lay of the Land early game is fine enough, you often only cast Demonic Tutor early game when you need to get a land as the tempo cost of spending two mana to do nothing is steep (obviously combo decks love to fire off a turn two Tutor but other decks not so much). In this role Traverse is far better than Demonic as it is half the cost! Late game you should be able to have delirium, otherwise you probably shouldn't play the Traverse. This is easy enough to do but is made a lot easier with sensible deck design. When you have delirium Traverse is one of the best tutors in the game. The cost is so minor and the range is very broad. Traverse has the best scaling of all the green card quality effects and that is typically the area in which they out perform the blue ones. Synergy and scaling.
Vessel of Nascency also arrived on the scene at the same time as Traverse. I overlooked the card somewhat based on the lack of success of Seek the Wilds. Given the results of PT Eldritch Moon however I think I need to give this card another go. Vessel does a lot more things than Seek the Wilds and indeed some more than Impulse. My early dismissal came from the feeling that three mana is too much to pay for card quality. This is an assumption brought over from blue card quality and may well not be the case. Three is a lot but green can likely stomach it best. Further to this the card is split into a one mana sorcery speed play and a two mana instant ability. Some times this will make it easier to use than Seek the Wilds. The range on Vessel is also huge, hitting every card type excepts instants and sorceries (and tribal kind of). Vessel is an enchantment itself which can contribute to delirium or devotion or do something extra synergic that was not the main function of the card. Lastly it puts things in the bin which is generally pretty helpful for a lot of green synergies including many other cards talked about today. While certainly the clunkiest the Vessel is the most powerful baseline and has the most it can potentially offer synergy wise.
Grapple with the Past is the most recent addition and probably the most powerful. It actually has a lot of similarities to Evolution Charm that I hadn't quite realised. Grapple is more direct and more powerful but Evolution Charm isn't a bad card by any means and may merit a little testing revisit. Grapple is the green Anticipate combined with a bit of Regrowth and a bit of Strategic Planning. It scales better late game and scales better with any graveyard synergies. It is pretty much Anticipate as your first play for finding you action or land drops and it is pretty much regrowth late game recurring you a juicy threat. Solid all round and even stronger when used with other cards on this list like Gather the Pack and Traverse the Ulvenwald.
Blue has more rounded card quality, it still has the premium effects and it still has the most. Green however has become the colour with the best card quality if lands and creatures are all you care about. Further to this the green card quality offers some of the best graveyard synergies too. Green has been the strongest colour in the midrange cubes for a little while and these cards all coming along together have only pushed green further ahead in cube and hands down the best colour in standard. Blue is still the most "powerful" cube colour but green decks do more winning and should continue in that trend. The real question is whether this surge in green power will allow it to topple red as the knig of cube!