The nuts change street by street. Good poker players realize that sometimes their very strong hands may only beat a bluff with the given action. Weaker players do not know that their own hand strength is actually irrelevant in certain situations—your opponent either has what he is representing or he does not. Let us take a look at an example. Say in a $1-$2 game with effective stacks of $300 we raise with Q ♥ Q ♠ to $10 and three people call.
The flop comes out very favorable for us—Q ♣ 3 ♠ 2 ♣. We bet out $30 and one person from out of position calls. The turn is a T ♥. Our opponent checks, we bet $70, and again he calls. The river is one of the absolute worst cards the deck a 6 ♣. Our opponent now open moves all-in for $190. So many times I hear inexperience players say in this situation, “I have a set I have to call” not realizing that their own hand strength does not matter. Their opponent either has a flush, straight or is bluffing. The fact that they have three queens is basically the same as having AQ or to a more extreme extent ace high if we think that our opponent either has a flush or a busted straight draw like A5.
It is very difficult for lower level players to fathom this concept yet it comes up all of the time. In many cases your very strong hand has the equivalent hand strength of ace high given the action of the hand and with what your opponent is representing. They simply have it or they do not. Now, this is a very extreme example and sometimes a set may beat a lesser holding that your opponent may be value-betting but especially when the scare card comes on the river—and often it is a third suit—people shut down with anything less than a flush. If they are betting big they ether have the flush or are trying to represent it. The strength of your own hand is irrelevant and a second nut holding may become just a bluff catcher.
Let us look at another example. We raise in position with K ♥ Q ♥ over one limper and get the pot heads up in a $2-$5 game with effective stacks of $500. The board runs out 9 ♥ 2 ♥ 3 ♠ T ♥. We bet both the flop and turn and are called on both streets. The river comes a 4 ♥ putting out four hearts on board. Our opponent now bets big into us on the river. We know that he is relatively passive and would not bet anything less than the king high flush. Even though we hold the second nuts our hand is basically the equivalent of holding no flush at all. He is either bluffing or has the nut flush. We know that he is not betting anything weaker for value.