I play magic. Well, at least I used to. Never competitively though, at least not in meatspace (or magic online, apprentice ftw). And I agree - there's a great connection to rationality. One problem with the game though: to truly enjoy it's dynamic nature, which is one of the great things that sets it apart from other games, it takes a significant continuous financial investment in new sets. It's the reason I never played competitively.

I'd wager that there's at least one other mtg player here. How many people are named Zvi?

There's a set of 3 (I think) articles on starcitygames that performed an act of reduction in magic theory. It was a great example that I kept going back to when reading Eliezer's stuff on reductionism. For those that know the terms, the author reduced tempo to a more general notion of card advantage. I'll try to track the articles down.

Edit: here are the articles. If you don't understand magic terminology... sorry. If you do, I think the articles are great from a theoretical perspective. However, from a practical perspective, the traditional notion of tempo may be more useful. I'm probably not a good judge of that, however. For one, I haven't read the articles in a while.

Part 1 Part 2 Part 3