1-ofs

Four 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 1-ofs. Single copies of a card in a deck is generally a mistake. The reason is that there will be many games of Magic where you never see the card. If you can win without ever seeing the card in a game, why is the card even in your deck? You should just increase the number of copies of some other card.

The Hypergeometric Distrubtion calculator from part 1 shows us that the probability of having your single card in your opening hand is only 11,6%.

So when do legitimately run a single copy of a card in your 60-card deck?

You can search for the card
A good example of this is the dreaded 1-land-spy deck in Pauper. It needs only one land because it can search for that lonely forest easily. Here is an example deck list: http://tappedout.net/mtg-decks/1-land-combo/

In the deck mentioned above, 1-land-spy in Pauper there is an example of this as well. You only need one kill card, Haunting Misery, because you will draw your entire deck and can then kill with it.

You can draw your entire deck
It is similar to being able to search for the card.

Your card is restricted
Congratulations, you are playing Vintage. You are awesome.

You really want to run 5 copies of a card
If you have a card that is a 4-of and you then want just one additional copy that means that the second card has to be a 1-of.

You need to run a single copy because of mana curve considerations
I think this is less likely to come up than it was for 3-ofs or 2-ofs. Stay away from 1-ofs if you can.