Percentages

[AaronBrown]

George Rice is correct, but you can approximate these things pretty well in your head. Calculators and tables have made a lot of people lazy.

Pocket 8's against AK? If no A or K shows up on the flop, 88 will usually win (straights and flushes to unsuited hands are rare, and don't even mention quads on the board). About half the time, neither of two cards will appear on the board. A few of those times, there will be a third 8. So it won't be any surprise to learn that 88 wins about 55% of the time.

The individual probabilities give you more detail than just knowing the probabilities of winning at showdown. Most of the time you don't get to showdown. 88 wins 55% of the time, but if one or more face cards shows up on the flop, it has to figure it's behind. If you fold it every time a face card and no eight is in the flop, you'll rarely win. But if you call raises in all those cases, you'll lose more the 45% of the time you lose than you win the 55% of the time you win.