@tom-bombadil said in Mentor Control:
Maybe it is not correct to still call it Mentor Control, but Jeskai or 4c builds that are based on cantrips, Delve-spells and Planeswalkers are still pretty strong, so I place my questions here.
Why do people not play the full set of moxen?
My Gush book answers this in far more detail , but...
In general, the "Xerox" decks that preceded Mentor rarely played full complements of Moxen, and usually stuck to on-color Moxen, and often omitted even tertiary on-color Moxen. The main reason is that these decks gain virtual card advantage by having a much lighter relative mana base than their competitors in the field. So, they prune mana for spell density. They compensate for this by having a much lower overall mana curve, which bends low or flat in the upper end, and rarely include cards that cost more than 3 mana.
Take a look, for example, at the UR Delver decks that were doing well in the summer of 2014. Those decks, even if they splashed green, often just ran Sapphire & Ruby. But, even if you go back further, and look at GroAtog decks from 2003 or 2007-8, they rarely ran full sets of Moxen.
The reason that I started playing full Moxen (and my list from the NYSE V this past summer is a case in point) was specifically because of Mentor. It turns out that Moxen were valuable to helping accelerate out a more expensive growing threat like Mentor (most "Grow" or "Xerox" threats in the history of the format were no more than 2 mana - Delver, Pyromancer, Dryad, etc. are all 1-2 mana (I have a whole table of such cards in my Gush book)). Mentor, being 3 mana, is challenge to the Xerox/Grow archetype, because it often means you need/want more colorless acceleration to both play your threat and then have a mana up to protect it with Spell Pierce/Flusterstorm/Pyroblast. Secondarily, but no less important, the virtual card advantage downside of drawing dead Moxen was mitigated by the fact that a Mox pumped Mentor and generated new tokens.
Very few of the Pyromancer/Delver decks from 2013 on generally played JTMS, either, which would also incentivize you to play full Moxen. Without full Moxen, it's hard to reliable Gush into JTMS on turn 3. So, the exception to playing full Moxen or more artifact acceleration in Gush decks that used lots of cantrips were decks like East Coast Wins from the summer of 2011, which were essentially just big mana blue decks with Gush. But, historically, most Vintage Gush decks in the Xerox mold do not run off color Moxen. There are exceptions, of course, but that's not the norm.
Another, third related reason, is that, at least since 2003, alot of "Xerox" decks will play Null Rod or Null Rod variants. Thus, running more Moxen makes Null Rod less asymmetrical. Contemporary Delver, for example, often has 2-3 Null Rods in the 75 somewhere.