Magic the Gathering is a game of numbers.  While there are elements of chance once the game has started, the object of the game is to try and skew these unpredictable factors to your favor.  You opportunity to manipulate these values comes well before the decks are cut or even sleeved.  It happens on the drawing board.

[caption id="attachment_441" align="alignright" width="227" caption="Elmo says: Numbers are Magical!"][/caption]

A typical 60 card Magic the Gathering deck will  consist of about 20 land and 40 other cards.  Of the 40 non-land cards you'll probably only have 15 or so unique spells to choose for the deck.  We all understand the basic concept:  If you really need the card, put in 4 copies.  Not as important?.. go for 2 or 3 copies or just take it out completely.  Not surprisingly, much more can be considered when choosing how many copies of a single card to play.   Since there are only 4 possible options for these quantities so lets go through each of them.

1 Copy - Typically you won't want to put only one copy of a card in your deck.  You are trying to control the outcome of the cards hitting the table and that is not helped by a card that you have a 30% chance of ever seeing.  If its not good enough to put more than one copy in, its probably not good enough for your deck.  Possible exceptions for putting a single copy of a card in a deck  include:  not physically owning more than one copy (easily remedied), unique land cards, particularly certain legendary lands that are often easily searched for- or your deck does a ton of library searching for that particular type of card.  But most of the time, if we're trying to play the odds, 1 copy of a card isn't going to cut it .

4 Copies - Most cards in your deck should be playsets.  The best way to control which spells you'll be able to play in a given game is to put as many copies of the cards you need in your deck.  When you decide that your deck needs a spell your first reaction should be to put in a playset in and trim back from there.

2 Copies - Putting 2 copies of a card in a deck should be done either when you are planning on using a "get card" to grab it from your library or if you're planning on it being an endgame, 8 mana blast that would be absolutely devastating to have more than one of in your hand at a time.  Use the "2 copy" option to trim down those playsets that have high mana costs or don't need to be played more than once.  The Alara "Ultimatum" cards come to mind.  The only thing worse than not having the right mana to play a card in your hand is to not have the right mana to play two of the same card in your hand.

3 Copies - This is a vague area that can be used in one of two ways.  Often you have your deck completely set and you realize that another card just has to be included.  Unfortunately, at this point the cards going into your deck cannot be removed.  You only need 1 more slot to put in that extra land you've decided is necessary and you have to choose one of your playsets to demote to "3".  Not ideal but sometimes it must be done to get a card or two that you need into the game.  Some decks just need more variation than others.  There is also that foggy area where you have a card that you absolutely need to get in a game but really do not want to be caught with more than one in your hand.

5 Copies - C'mon, no one'll ever know!

Alright, enough blather, lets take a look at a real, live Top 8 deck from the recent LA Grand-Prix:

[caption id="attachment_436" align="aligncenter" width="386" caption="2nd place 2009 Grand Prix, LA - Congrats Brett"][/caption]

Notice the mix of card quantities?  Mostly 4's, a couple of 3's and 2's.  A recent trend I've noticed in rush decks is to try and keep your land under 20 to get your chances of drawing non-land cards up.  My guess is that Brett would like to have put 4 Myr Enforcers and 4 Thoughtcasts in the deck but needed the slots to get the Blinkmoths or Fatal Frenzys in and had to choose a couple of cards to trim down from 4 to 3.  Fatal Frenzy is also kept at 2 because it is more of a "finishing move" and would not be effective if you ended up with 2 copies in your hand, particularly at the beginning of the game.  The pair of  Atogs is a great example of a card that, simply due to its self destructive nature, cannot be played more than once or twice in a game.  Learn to think like these guys and keep dead cards out of your deck.  You'll do great in both casual play and tournament play by .

So next time you're trimming those last few cards out of your deck to make way for your final playset, take with you what has been discussed here.  If all else fails and you just cant decide, ask yourself  "on a scale of 1-4 how badly do I want this card in my opening hand?"  Sometimes you just need the card and the conversations about somehow getting 2 or 3 at the same time go out the window.  But for those more ambiguous situations I hope you have the tools to help you you make better card choices.