Knowing the hand ranks gives a player a quick signpost for their strength when betting into a pot. A successful online poker player needs a detailed knowledge of the hand rankings. When I say you need to know the poker hands, I’m not talking about whether a pair of aces beats a pair of kings.
I’m talking about that mass of card combinations between the best and worst hands. Whenever you hold any set of cards, a gambler needs to know its strength relative to the rest of the possibilities. To do this, card players should study hand ranking charts not much different than what you would study in blackjack.
Several experts have made tables which detail the playable hands in Texas hold’em, Omaha, seven-card stud, razz, and the various hi/lo 8-or-better variants of the games already mentioned. Study these for the game or variant you want to master. That way, you know which hands to play and which to fold.
Even if you decide to play a hunch or make a bluff, you do so with the knowledge that you’re diverging from classic poker strategy. Predicate all you do in poker on a firm understanding of the hand ranks.