With only 169 different two-card starting mixtures, studying to perform them is not as difficult as you may think. Pairs of the same rank have equal worth before the flop. So do similar suited cards. For example, prior to the flop, 9s-9h is equal to 9d-9c, and Kc-Qc is just as worthy as Kd-Qd. But if the flop contains 3 diamonds, then the Kd-Qd may be priceless, and the Kc-Qc is unplayable.