Hi all, I'm not exactly a math nerd but I often work on this kind of problems.
Your approach is good but at the same time it's false.
good : you got a kind of objective view of the proportion of quanta in your deck. You add some variable to have a better guess.
Bad : most of time people think their deck as a block. got 40 cards, got 3 nova -> got 3/40 chance to draw nova.
A better way of thninking a deck is water. You got a flow of cards, and what is important is the way the card come.
All of this is only probability. conditional probability to be exact. When you try to guess if you got enought pillar, you are asking for something very very complicated. Your question could be "after taking 7 cards, what is the probability to draw the card I need".
Let's try something, just divide card into three classes : pillar, creature, spell. with a 40 cards deck as follow : 10p/20c/10s.
probability to successively draw pillar is : 10/40 (first draw), 9/39 ( second draw ), 8/38, 7/37 and so on....
if you understand all, probability to successively draw a creature cards is : 20/40, 19/39, 18/38 ....
so the probability to draw 3 pillars as the three first cards is : 10/40 * 9/39 * 8/38 = 720 /59280 = 0.01214
but probability to have 3 pillars in your first hand is very different :
you can draw pillar like this (the possibility area ) P is for pillars, C for other cards
P P P C C C C -> this one is 0.01214
P P C C C C P
P P C C C P C
P P C C P C C
...
C C C C P P P
probability of the second line is :
10/40 * 9/39 * 8/34 -> 720 / 53040 -> 0.01357
Probability of the last line is : 10/36 * 9/35 * 8/34 -> 720 /42840 -> 0.01680
This is not exactly what we want to know. Go back to the question : your are right when you put your QI,it'is the number quantun I need to play. I element there is something diffrent from MTG, your quantum is a pool were quantun stay until it's used. Appear another question : how many time can I wait to play my card ? Does it make a difference if I can play my card in the second turn instead of the third one ? answer to this question depend of how the game occur. In the first turn you can wait. In the last turn you can't.
an easiest question : knowing the probability to draw a pillar in the eigth draw knowing that I already draw X pillar ?
I don't what to tell you that your idea is wrong, it seem to be a good tool to estimate a deck. But if you want to be very accurate in deck building the road is long and complicated. Two things worth knowing : richard garfield (mtg) build is game when he was studying probability (and now he is a mathematic's doctor, speciality : probability
) . Most of Pro MTG player are now pro poker's player.
PS: I write all of these in a raw without coffee, It's (surely) confuse, I'll try to re-write it latter...