When many people think about cube they think of it as a very organic and loose process without having much with regards to the numbers behind the cube design process. When looking at decks on this site from various events we're given access to statistics like average converted mana cost and overall card composition by color and type. While it's easy to break down types of cards like artifacts and creatures in a cube and while many deck designers use statistics like average converted mana cost for their decks they don't use things like converted mana costs in their own cubes. When looking at a cube to critically evaluate it I like to be able to use various forms of data to help analyze it to look at the cube's overall picture and to help to make critical evaluations.
In this article I'll be discussing how to use various types of data in cube design and evaluation using some metrics to help understand certain facets of cube as well as helping to understand various types of trends and information found in your cube.
When I started to build my cube there wasn't anywhere near as much information about cube design and other cubes to consult as there is now. I consulted various lists but noticed that I couldn't tell very much from many lists as many were mainly just an alphabetical listing of their cube's contents. This was useful if I wanted to know if a certain card was in the list (is this person running Opposition/Deep Analysis in his list?) but it didn't really say anything about the cube's contents aside from Tom LaPille's list which had a sorting by converted mana cost for each section. There's a maxim that the amount of one-drops and two-drops in a cube is a pretty good barometer of the aggressive support in that cube and unfortunately an alphabetical list did little to help with this. When looking critically at a cube to understand a cube's environment as well as when making changes to my own having the cards sorted by mana cost is crucial as it lets people critically evaluate the mana curves in each color and section. I recently saw a post on friend's cube thread about how his cube was running too many six-plus-mana white cards. His cube thread had a listing which was broken down by section and had the cards arranged by casting cost; without using that method the insight may have been overseen as sorting cards by the mana cost helped identify the mana curve in white and the cost at 6-plus-mana.
When sorting cards by mana cost it's important to sort them by their actual mana cost and not by their literal mana cost. I'll go more into calculating average converted mana costs later but at this stage it's important to make this distinction because it helps to show how the environment is actually playing out (at least at the mana cost level) rather than what's merely printed on a card. Using its actual cost addresses how the card actually plays in a cube.
For example although Rude Awakening may make you lose five life when it's revealed to a Dark Confidant for the majority of the time in cube it gets cast as an eight-mana spell; seeing a list/sorting of a cube with Terastodon and Woodfall Primus in the eight-mana section but Rude Awakening at the five-mana slot doesn't really reflect the cube environment having three eight-mana effects in green; it looks like there's just two. The same works with X-spells being sorted at one mana because unless someone's trying to kill something with the skulking drawback (Phantasmal Image/Makeshift Mannequin) or unless someone got Mindslavered putting X spells like Devil's Play as one-mana spells is disingenuous as Devil's Play doesn't belong at the same mana slot as Goblin Guide and Grim Lavamancer.
Besides when you're looking to make changes via additions/cuts in your decks you generally sort by mana cost and when using cards like Rude Awakening whose literal cost doesn't usually match its actual cost you generally put it in your deck at the actual eight-mana slot. Why should your cube layout be an exception?
The Value of Spreadsheets (or writing things down)
One of the most useful pieces of data when looking at a cube is calculating its average converted mana cost as it's definitely a big help when evaluating the strengths and weaknesses of the sections of your cube. Calculating it is one of the first things that I do when going deep into the think tank when evaluating someone's cube.
I keep a list of my cube on my blog but even if I didn't have a blog I'd still keep a listing of my cube's contents in electronic form such as an OpenOffice (which is open-source)/ Microsoft Office Word sheet. Even if I didn't want to use it for analysis it's useful to keep the contents of a cube organized.
The formula for finding the average mana cost is pretty easy but this page explains how to do it in Excel/OpenOffice. I definitely recommend using either one of these programs to calculate the average converted mana cost as it's really tedious to do by hand. If you don't want to do that you can use deckstats.net which also calculates converted mana cost averages (as well as being able to change the mana costs such as being able to enter cards like Spectral Procession as WWW Force of Will as zero and to ignore the cost on X spells to truly reflect their actual mana costs.) Why bother you say?
Much like the maxim about the amount of one-drops and two-drops being a pretty good barometer for aggro support in cube the same generally applies to looking at the converted mana cost average in a cube as a lower overall mana cost generally implies a more aggro-friendly environment. Granted this method isn't perfect as there are plenty of cheap cards that have no business being in aggro decks such as Condemn and Innocent Blood. However a lower average converted mana cost is a pretty good barometer of the (mana) efficiency of the cards in that cube. In cubes where the average converted mana cost is higher efficiency is generally less of a factor. This coincides with aggressive deck support as aggressive decks with efficient cards generally punish inefficient control decks for not doing much with their mana.
Pre-Dark Ascension the average converted mana cost in my cube was at 2.8372. Cubes should definitely have their average converted mana cost to be under 3.5 (and that's a high ceiling at that)—although different constraints can change this: not including power and rarity structures being the big ones (the latter because high-cost finishers in Pauper and Peasant cubes are pretty scarce with cards like Errant Ephemeron and Serra Angel being amongst the cream of the crop for finishers in those formats).
However looking at the average converted mana cost isn't just a tool to make aggressive strategies more viable. The more important thing is that when looking to lower the average converted mana cost helps you look critically at each card especially that each card is pulling its weight at the respective cost. It's something that's generally done when keeping Kaizen in mind but it's especially important because when looking to reduce average mana cost. You look for cards that aren't pulling their weight and it makes you critically evaluate the role of every card at its mana cost. When setting small goals for lowering the average converted mana cost like reducing a cube with a 3.3 average mana cost to a 3.2 it truly helps cube designers to fully realize Kaizen and how important it is for each card to not just be not a bad card but one that competes effectively with all of the other cards in the section (as well as strengthening them through support).
Granted it can be hard to compare vastly different cards at the same mana cost—is Graveborn Muse better than Skinrender? Is Mirror Entity better than Blade Splicer? While people can have different answers to these questions (I'd say Skinrender and Mirror Entity respectively) the main thing is that it makes you ask yourself these difficult questions in card evaluation. Of course this method shouldn't be used to force cards that shouldn't go out of your cube but this method definitely helps finds cards that aren't doing enough for their cost. I cut Masked Admirers from my cube when critically evaluating four-drops because it wasn't performing at the level of other green four-drops in my cube. But I wouldn't cut Skinrender or Graveborn Muse because neither is performing at a significantly lower level than other comparable (four-drops in black) cards in my cube.
This method also makes you ask these questions when looking at these cards when drafting someone else's cube. "What is this Farhaven Elf doing in this pack? Why is this in here?" Maybe it doesn't really belong if the other three-green mana spells you've seen have been better. Maybe you're safe to effectively ignore that card!
Adam Styborski who has a very good Pauper Cube blog has a detailed cube template for his own cube. Even if you don't feel like downloading OpenOffice and using a spreadsheet or a homemade spreadsheet his template can give you some ideas for organization for your cube list; that information can be used to effectively analyze your cube such as "tagging" cards with whatever their archetype(s) and general purposes are even if you're just writing those notes down in the margins of a notebook. For example Bloodghast could be tagged as an aggro card as well as being a Braids/Smokestack card. The level of detail is up to you as you can categorize things like creature type where Bloodghast's Vampire type is relevant (for cubes using Bloodline Keeper). This is more a factor for tribes such as the Zombie tribe that has recently been given more interactions lately presently supported by Sarcomancy Graveborn Muse and Gravecrawler in many cubes (and sadly that's about it for major tribal support in a regular cube). Being able to quickly identify cards by interactions and archetypes can quickly let you analyze how cards interact and give more support to cards if need be. "How many ways can I kill Abyssal Persecutor in my black section? I can check."
Spreadsheets are also useful for being able to keep track of what editions of cards are being used or other things like "pimp status" such as if a card has been foiled altered or autographed.
You can also monitor other things like the percentage of time that a card sees maindeck play which was something that I used to do but don't any longer due to time constraints. Much like using the average converted mana cost method this method isn't perfect either—powerful cards like Ancestral Recall trend towards being played in the maindeck a majority of the time but sometimes players can take cards with non-splashable costs or ones that don't fit into an archetype and find that they can no longer play the card in their deck like taking an early Sulfuric Vortex and being shipped a bunch of Dragons or taking an early Sorin Markov/Vorapede and getting cut off in the color. Usually the universally playable (in both aggro and control) cards like Elspeth Knight-Errant Lightning Bolt and Fact or Fiction were ones that ranked the highest but it wasn't a guaranteed of high percentage of play (people aren't going to play suboptimal cards even if they're universally playable). Whereas the archetype-specific cards especially the ones like Smokestack or Life from the Loam don't tend to get as high percentages but still get a good amount of maindeck play.
There can also be times when people don't know how to use a card or grossly underrate the card; I was talking to someone who had Blast from the Past but found that it had seen little play but that was mainly because people didn't know that you could cycle it and play it with madness cost (a la Ichor Slick for those who remember Time Spiral-era block Limited). When a card doesn't get played I found it useful to write the reason why the card wasn't played to help when looking at a card's record in cube. This is a more tangible method of finding out whether cards are being played; it can help quantify whether cards are being played versus feeling like you've seen a card sit in the sideboard a lot of times.
You can also track data such as the winning percentage of cards and archetypes. A critical point when it comes to archetype support isn't just that someone can draft it but whether people are being given proper incentive to draft the archetype by having the archetype be a consistently winning one. Tracking archetypes in a spreadsheet (or even on paper) can help you quantitatively measure exactly how archetypes are doing in your cube. How often are people drafting R/B disruption-heavy aggro decks? How often are people drafting decks with three or more planeswalkers? How often are those decks winning—are they decks people want to draft or are they the decks you'll see in the losing bracket? It's especially useful when testing support for new archetypes; I've recently been giving some more support to mono black/heavy black archetypes and I'm tracking their success in a spreadsheet.
All in all keeping track of these types of things helps you to keep track of what's important to you for your cube. Even if it's something like a cube achievement list for things like the times that someone lost after a turn 1 Library of Alexandria or after restarting the game with Karn Liberated. It's all up to you!
I hope that this article has given you some tools to critically evaluate your cube by means of data.
May all of your opening packs contain Sol Rings!
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My blog featuring my powered & pauper cube lists: http://idratherbecubing.wordpress.com