There are two primary reasons for making a bet or raise.

1. To get value when it's likely you have the best hand. This is a value bet, and it's a bet you expect to be called by worse, allowing you to win a bigger pot at showdown.
2. To fold out better hands. This is a bluff, and it relies on fold equity. You don't want your bluff to be called. You want to win the pot down without a showdown.

Some writers or commentators will talk about making a bet to “find out where he's at”, but information is a side-effect of betting, not the purpose.
At 2NL, you should seldom bluff, apart from when you make a continuation bet. Sometimes you'll make a c-bet with ace high, but you actually have the best hand, so your bet has both a value and a bluff component. Winning small pots with ace high is all well and good, but the real money in poker comes from extracting value when you have a strong hand. At 2NL, value-betting your strong made hands is particularly profitable, because villains will call far too often with weak hands and draws.

Newcomers to poker often say things like “I shoved my overpair on the flop, because I didn't want him to hit the flush.” Viewpoints like this show a fundamental misunderstanding of how we make money. If you have TPTK or an overpair, you should welcome calls by drawing hands, because it is these calls that bring your hand its value. After all, a draw is only going to complete on the next card about 20% of the time. Four times out of five, your hand is getting a street of value. Correctly sizing your value bets when you believe a villain is on a draw is a crucial skill to master. (See JWK24's brilliant blog on this subject.)

Another common mistake occurs when hero flops top pair and gets bet into. Hero raises, and the villain either folds (so no additional value is gained) or villain re-raises (because he can beat top pair). It is usually a mistake to raise with one pair hands, because it's hard to get action from worse. If a villain bets into your TPTK (possibly with a weak hand or draw), you get value by calling the bets, because the villain will have to put more money in the pot on the next street (often by continuing with his bluff) if he wants to win the hand.
When making a bet or raise with a hand that has showdown value, remember that if worse hands can call, then it's a value bet. If worse hands cannot call, then you're pointlessly turning your hand into a bluff and you're value-cutting yourself.

Now let's take a tour of Valuetown.

Valuetown is a picturesque holiday location known well among winning poker players. This little town has just three connected streets, which the cognoscenti call the Flop (a ragged alleyway with no obvious destination), the Turn (an important street with a clearly defined route) and the River (a major street from which there is no turning back). At the end of these three streets is a magical object: a machine that can convert playing cards into cold hard cash. Only skilled operators can use this machine, which they call Showdown.
To a first-time visitor to Valuetown, showdown sounds like a wonderful treat, but for most of the tourists this destination is a big disappointment, because the Showdown machine rejects their cards and sends them to the muck.

If you happen to visit Valuetown, it's better to be the bus driver collecting the ticket money than the passenger paying for the ride.
When you make a standard pre-flop raise with a decent starting hand, you are the bus driver and you're looking for customers. You're saying: “Bring your cards for a ride to Valuetown! Only 6c to see the first street!”
When your customer pays 6c to see the flop, he is visualising the turn and river further up the road. If the tourist wants the opportunity to turn his cards into cash at showdown, you want him to pay for it, by collecting money from him as you travel along the three streets to get there. The closer you get to showdown, the higher the price you should charge, so that the money in the pot grows exponentially. You might, for example, charge 6c to see the flop, 10c to see the turn, and 25c to see the river. When you reach the end of the road and your customer is in touching distance of showdown, you want to charge him again. If you set a price of 45c and he pays up, then a bus ride that started with a tempting price of 6c has ended up costing your passenger 6+10+25+45 = 86c. Now that he's travelled so far, the tourist will usually be willing to pay a high price to try and turn his cards into cash, but often his cards are useless. The Showdown machine rejects them. You make 86c profit and the passenger has nothing but memories of what might have been.

There's clearly a lot of money to be made if you can repeatedly take customers to Valuetown when they have losing cards. Sometimes, however, you'll be driving towards showdown, feeling confident that your passenger has bad cards, but he will do something surprising. He'll offer you extra money if you can get him to showdown more quickly. By this, I mean he raises the price on his own initiative. At this point, you have to hit the breaks. If a passenger is willing to pay a higher price than usual, then he's very confident he has good cards. Since you don't want this passenger to take money from the showdown machine, you should stop the bus and cancel the trip. If you allow the tourist to set the price, you've effectively given him the keys to the bus, and now you're the passenger being taken to Valuetown.

When we are considering putting money in the pot on every street, we want to do so with hands that are likely to win at showdown. If we're bumping up the price on every street of Valuetown, it is crucial that we win more than half the time in order to make a long-term profit. Since it's imperative that we have the best hand at showdown the majority of the time, the implication is that when we suspect we will not have a winner, we should fold on an earlier street before the pot becomes large.

To jump out of this metaphor and put it in straightforward language, our basic strategy is one I trailed in my last blog: We will bet for value when we we think we are ahead, hoping to win a big pot at showdown, but we will minimise our losses by folding when we have reason to believe we do not have the best hand.

A further distillation of this idea is this: We make money at 2NL by winning big pots, and losing small ones.

This concept is illustrated by the graph below, which includes my showdown and non-showdown winnings (aka losses), along with my net winnings over the 98k hand sample featured in Part 1.

My net profit of $176 (green line) is the total of my showdown winnings (blue line, $354) minus the non-showdown losses (red line, -$178 ). (It's a weird coincidence that my losses when I folded before showdown are almost equal to my total profit, but recall that I ran $60 below EV, so with “average luck” my blue and green lines would have been higher.)
When I was in a pot that reached a showdown, the blue line was impacted. If I made a profit on the hand, the blue line went up. If I lost the hand, it went down. I won about 53% of hands in which I saw a showdown, so mostly the movement was upwards, especially as I made sure most of the hands I won were big pots. Most of the pots I lost at showdown were smaller ones because the villain missed value and gave me a cheap price to call with my marginal holding.

The red line was impacted by hands with which I did not see a showdown. Sometimes I won a small pot with a pre-flop raise, a 3-bet, a flop c-bet, or a turn barrel. Often, however, I put money in the pot on an early street, but folded to later action when I realised I had little chance of winning. Included in the redline losses are all the blinds I paid when I declined to call and see a flop.
Players of higher stakes and 6 max might laugh at my red line. It's textbook “weak tight nit” material. This isn't a problem, because “weak tight” is a profitable style for FR 2NL, where the blue line is far more important. It is absolutely standard to have a negative red line in full ring games at the lowest limits, because we will be folding post-flop when we feel our hand is beat, and folding pre-flop (especially in the blinds) very often. It's possible to have a positive red line, but it requires a looseness and level of aggression (including bluffing) that is neither warranted or even advised at peanut stakes. I may provide some tips on how to your improve your red line in the future, but for now it's unimportant. Besides, when the red line goes up, the blue line tends to go down, leading to big swings in the size of your stack/bankroll. As emphasised throughout this course, beating 2NL with relatively low variance requires solid value betting and showing down the best hand. To put it more brutally: If you have a strong hand in a pot against a calling station, value bet, value bet and value bet some more! Take the fish to Valuetown and get that blue line going up.

To stand a good chance of having the best hand at showdown, we want to begin with decent starting cards. That will be the subject for the next blog. Get ready for some hand charts that you can use as tickets to Valuetown.

Questions, comments or suggestions are welcome as usual, but note that I'm more likely to see and answer them in my blog thread on the forum.