What are the Pros and Cons of using cards from multiple different sets when drafting?

Question

My friends and I have never drafted before and are planning to try it in the next few weeks. However, one thing we're not sure of is whether its better to mix cards from different sets or just have them all from one set (We're actually just using random cards selected from my copies of the sets and not boosters, but I don't think that will make a difference for this question). Currently I'm planning on having the first 2 rounds be all M11 and M12 mixed together and the last round be Innistrad, but I don't have any reasoning for doing it that way and am curious what others think.

Are drafts normally done with boosters only from one set, or from different sets? Why are they done this way? If multiple different sets are used, should the packs from that each set be all used in one round or used one in each round (1 round of all Innistrad packs vs. at least 1 pack of Innistrad mixed in each round with whatever the other packs are)?

Answer 1

Normally drafts are restricted to a single block.

In sanctioned drafting (with sealed boosters), the distribution looks like this:

• Core set, the first set of a block, or a "big third set" like Rise of the Eldrazi or Avacyn Restored: three boosters from the same set, e.g. M12 / M12 / M12.
• The second set of a block: one booster from the new set, two from the first set (which is bigger), e.g. Dark Ascension / Innistrad / Innistrad.
• The (small) third set of a block: one booster from the third set, one from the secondset, one from the first set, e.g. New Phyrexia / Mirrodin Beseiged / Scars of Mirrodin.

(Note that, before Scars block, the pack order was reversed.)

As you can see from the list above, the size of the potential card pool will vary. M12 / M12 / M12 has around 250 possible cards. NP / MB / SOM is closer to 600. Thar larger card pool is trickier for players to learn (folks who play regularly will learn it incrementally, as new sets are introduced). I've heard of triple small-set drafts (e.g. Worldwake or Eventide), but many players say that these have very stilted environments -- both because the card mix is to small and because they were never designed to be drafted stand-alone, so a lot of the card pool assumes you'll have cards from the other set to round out your deck.

The main advantage of staying within a block is that block themes provide players with a reference point for making draft choices. Stepping outside of a single block presents players with additional challenges in evaluating cards against the "metagame" of the total card pool. This may be desirable if you're specifically looking to force players to think on their feet in an unfamiliar situation, but novice drafters have enough to worry about without the extra complexity.

Generally, the cards in a block are all designed to work together (in draft more so than anywhere else, actually -- only some of the cards in each set are intended to be "Constructed-worthy"). When you stray from that structure, you risk watering down the archetypes built into a set / block. For example, M12 has a lot of bloodthirst creatures in it. Red and black, the two colors with the highest concentration of bloodthirst, have access to common-level "enablers" to make bloodthirst decks run smoother: Goblin Fireslinger and Tormented Soul. Mixing up M12 and M11 cards would make it more difficult to draft bloodthirst due to the lower probability of finding these cards (although you might be able to compensate with M11 cards like Lightning Bolt and Prodigal Pyromancer). It's not to say that you can't break up blocks, but ideally you should have a pretty good reason for doing so. In particular, watch for sets with "parastic" mechanics like Kamigawa's soulshift -- diluting the card pool with cards from another set will greatly weaken these cards, making for a wonky and unbalanced drafting environment.

As I said in this answer, I don't think absolute pack-for-pack correctness is super important in a DIY draft, because I don't like going into pack 2 knowing you're absolutely "cut off" from any more set 3 if you didn't draft them in pack 1.

Answer 2

@Alex P's answer is fantastic and explains in great detail why competitive drafting is always from the same block.

In a friendly game that is less competitive the things you need to consider all:

1. As he said, it will affect the metagame. Card drafting guides and strategies built up for drafting cards will be somewhat less applicable.
2. Some cards are meant specifically to work with a certain type of card, and if that type is rare, then those cards might be less valuable (many cards from the kamigawa block assumed a spirit-rich environment...)
3. On the flip side, some cards may not have a good answer since they were relying on certain things in the block.
4. Different blocks sometimes have somewhat different power levels.

Whether those things are advantages or disadvantages depends partially on your point of view, particularly the way it will affect the metagame. If I am someone who knows how to play but I haven't studied the current metagame, I might for instance prefer some weird mix of blocks so that effectively no one has studied the metagame.

On the other hand, if I am preparing for competition I might not want anything from outside the current metagame, much less a weird mix.

The bottom line is that blocks were designed intentionally to be cohesive. Breaking that cohesion isn't necessarily good or bad, but it will make the game more random in some ways.