Differences between Tournaments and Cash games

OK, so I've started playing a lot more NL cash than tournaments and here are my thoughts about the biggest differences:

Types of Players
In a tournament the perfect opponent is a TAG - meaning a guy who only plays the top 10% of hands and plays them aggressively without being tricky at all. Why do you want your table full of these guys? Simply because you will always know where you are and you can steal their blinds with impunity. Blinds are the key to winning tournaments - if you can steal twice per orbit every orbit you have no problem - you're going deep the vast majority of the time, and when you get there you'll win a lot. The tighter you're opponent the better.

How does this differ from the type of opponent you want to face in a cash game? Well, in a cash game it's very hard to extract money from the same TAG players that you're looking at in a tournament - when they play a pot they have a good hand and you have to outflop them. Players who are very loose aggressive, on the other hand, are great for you. They build big pots with marginal hands, they bluff more and in general make a game much more lucrative. Why? Simply because they induce other's to put more $$ in the middle with weaker holdings. Now, if the LAG is a weak LAG (meaning very spewy) that's great because you can make a lot of $$ off him and off the players who are opening up their ranges (especially if they open up beyond their ability). If it's a strong LAG, it's a bit harder, but the game will still be more profitable than one filled with TAGs.

I'm not saying that a 'rock garden' as it's come to be known is not profitable - in fact it's probably one of the easiest games to make $$ in - you're just looking at a grind winning a lot of small pots and staying away from big ones and a fairly steady, small earn rate. Loose games in general will be much more profitable because there's more $$ flying around - and you can play more hands with implied odds. All of this adds up to you're edge being implemented across more hands in bigger pots resulting in more profit, along with much more variance. This is why I'd always pick a game full of 'crazies' vs a game full of 'tight good players' (that terminology is from the home games I go to).

Bluffing
Every player sits down at a table with a preconception - everyone expects to be bluffed a certain percentage of the time. An extreme example is Player 'xyz' who thinks that no one ever bluffs; he starts playing you and after 100 hands notices that you showed down 2 draws that missed and you bet strongly on flop/turn, the wheels start churning and he thinks that possibly you bluff sometimes - maybe 5% of the time*. So now, he calls only you down a tad more often. As you continue to play his take on your play will move back and forth as you attempt to adjust how often you’re actually bluffing. While this variable is impossible to measure, it definitely has a huge impact on the success rate of your bluffs.

Another element that effects how successful your bluffs are is how often you play the same opponents. Tournaments have you facing opponents for short periods of times and seldom do you see the same opponent over and over. Cash games differ in that you can hunt for a specific opponent or he can hunt for you, in general you're much more likely to play the same opponents in a cash game than a tournament**.

The two most discernable variables in the success of bluffs are ‘Bluffing Frequency’ and ‘Bluffing Perception’. Bluffing frequency is just how often you are bluffing; whereas bluff perception is how often you're opponents think you're bluffing. If you're playing good opponents the two will be fairly close together. If you're playing bad opponents they will either over or under-estimate you're bluffing frequency. Against players who have a high bluff perception you're bluffing frequency should decrease because they will fairly often assume that you are bluffing. Against players with a low bluff perception you're bluffing frequency should increase, because they assume you have a hand when you bet.

Your bluffing frequency and as a result your opponent's bluff perception should never be static. As your bluffing frequency increases you are bound to have to show down a bluff. As you show down more and more bluffs your opponent's bluff perception should increase***. The effect of this is that your opponent's bluff perception goes up and you in turn need to compensate.

In tournaments, you rarely want to be caught bluffing. This is because the amount of chips lost will usually not be made up for by an incorrect assessment of your bluffing frequency. Contrastingly, in cash games this see-saw of bluff frequency and bluff perception is vital to your profitability.

What happens if a player doesn't adjust their bluffing frequency? Well, in general this is bad if you play an opponent for any length of time - it's bad because in essence you make yourself predictable. In this scenario your opponent's bluffing perception will converge with your bluffing frequency over time.

* This is assuming some cognizant thought by your opponent.
** In live play (especially home games) this differs because the pool of players is much smaller than online. However, this same small pool of players exists at the higher stakes in online games.
*** Once again, this is assuming they pay attention, and have any common sense - I know a lot to ask for.