Opening Holdem Hands

Here's a more mathematical (and perhaps somewhat more complicated) look at pocket cards in Holdem. From the article:

I wish to introduce some mathematical structure into the discussion....Much of the acrimonious discussion on the ranking of pre-flop hold'em hands arises from the fact some people are talking as if the 169 possible hands form a linearly ordered set. I am going to argue it is a mistake to think this way. One big problem is that the relation defining the ordering is terribly fuzzy. That is, in certain cases the notion of one hand being better than another hand is not clear-cut. In my opinion, the best thing to do for problem comparisons is simply to agree there is no order between them. In other words, treat the 169 hands as a poset.