3-ofs

Two weeks ago we discussed Hypergeometric Distrubtion and introduced this series. We also discovered that if you run four copies of a card in a 60-card deck you have a 40% chance of having at least one copy in your opening hand.

Here is the introduction: http://mtgolibrary.blogspot.se/2015/12/1-ofs-2-ofs-3-ofs-and-4-ofs-and.html


This week we are talking about 3-ofs. As an example we will be using Spire Golem in Pauper Delver decks.

The Hypergeometric Distrubtion calculator from part 1 shows us that the probability of having at least one Spire Golem in your opening hand (if you run three Golems) of 7 cards is 31,5%.

Here we have to consider another factor. By turn 6 you have a 12% chance of drawing multiple copies of your 3-of card. This means that a big finisher or something for the late game is probably not a card you want 3-of (Rolling Thunder in Pauper RUG Tron is a good example here).


So when do you run 3 copies of a card in your deck?

You want to be sure that you can draw one copy of the card in most games
This card is good and you want to see a copy of it in almost all games you play.

This also implies that you don't want as many copies of the card as possible because then you would just run 4-of.

You really want to run 7 copies of a card
It is hard to think of a situation where you don't want 8 copies of a card but exactly 7 but those situations may occur. In this case you have found a second card that is similar enough to the first card (that you have 4-of) so you are including 3 more.

Your 4th copy is in the sideboard as a wish target
This is a corner case but if your deck can fetch cards from the sideboard the fourth copy needs to be there to be fetched.

You need to run 3 copies for mana curve considerations
If your mana curve needs exactly three cards of this cost you have a good case for a 3-of.

I think that is what happened with Memnite in this Modern Affinity deck: http://www.mtggoldfish.com/archetype/modern-affinity-8972#online

This includes situations where you have to cut down to 60 cards from 61 and something just has to go. Remember, though, that the likelihood of seeing the card in your opening hand has been reduced by almost a third.

If having more than one copy of the card in your starting hand is a problem, consider running three copies of the card
We mentioned this last week. If a card is critical to your strategy but would be problematic in multiples in your opening hand, you should not run four copies of the card but go for three.

A good example of this is Armadillo Cloak in Pauper Hexproof decks. This card is an excellent card for the deck but having two cloaks in your starting hand will make you very slow. Thus, do not run four of this card.

here is an example deck list with three Armadillo Cloaks for this very reason: http://www.mtggoldfish.com/archetype/pauper-hexproof-22844#online