Betting Strategy
Now we'll talk about betting strategy a bit (the outs discussion is about calling strategy). So, you must decide when betting is +EV. The key here is that you don't just bet when you have a good hand, though that's a decent start. You bet for two reasons -
1. To get people to fold better hands (or dangerous hands) and win the pot right now, or
2. To get inferior hands to call (so they'll pay off on the show-down).
Notice that if you bet and inferior hands fold, or better hands call (or raise) - your bet was a losing action (even though you may still win the pot).
Now, betting in the early rounds is usually simpler. The basic idea is this - if you're on a "draw" or have a weak hand, you want to see more cards for as cheaply as possible. If you have a pretty good made hand, you want to bet, so that other people are charged to see cards. The key principles of poker are - you make money when other people make mistakes, and it's good for you to put them in hard decisions, and you never want to let them do what they want. eg. if they want to see free cards, you need to charge them.
Whenever you have a chance of winning better than 1/N for N players, it's good for you to get more money in the pot (though it may be even better for other players). For example, if you're just on a flush draw, if there are 6 players, it's profitable for you to get as much money in the pot as possible (assuming everyone will call). Of course if you have a chance of winning >= 50%, it's profitable for you to get money in the pot no matter how many opponents there are. Remember that you have two ways of winning - if they fold now, or if they call and you show down and win. Sometimes you may have only like a 30% chance of winning a showdown, but there's also a 30% chance your opponent will fold. The result is that you have a 60% chance of winning overall, and betting is profitable. In fact, this is so important that if you know your opponent won't fold, it's rarely profitable to raise.
Also note that if they fold they're giving you the *whole* pot, and you're only risking a bet. So, say the pot contains 20 bets, and you know your opponent will fold to a bet 10% of the time. If he calls, he has a better hand than you and wins the pot. You only have a 10% chance of winning, but you should always bet. The reason is that he is folding too often, so your EV is positive. EV = p * w - b = 20 * 0.1 - 1 = 1 bet. On average you win 1 bet by betting. You should be able to see that a correct amount of folding would be more like 5%. So, if he's folding 10%, that's clearly too much, that's a mistake by him, so it's profitable for you.
Much of betting strategy is based on them making mistakes. If they fold too much - you should bet more often. If they call too much, you should bet your good hands, but not your bad ones. If they check-raise too much, just check behind them with weak hands and bet with very good ones (expecting a raise).
One thing to consider with betting is whether you want to get people out of the hand or not. Often by betting you will put pressure on people and possibly make them fold. Generally, you want people to fold if you have pure junk (a bluff) or a weak hand which you don't expect to hold up at showdown. If you are pretty sure your hand will hold up at showdown, you want as many people as possible to stay in and call lots of bets. Also, if you have a strong draw, you want a lot of people in calling lots of bets. A draw like a flush draw is good against 3 or 4 people, but is very poor heads up. The reason is that heads up, you are only getting paid 2:1 instead of 3:1 or 4:1, and you only have a 35% chance of making your flush over two cards.
Let's consider an example. On the flop, you make a full house! You have a monster; someone before you bets. What do you do? Typically just call; you don't want to raise, because you want as many callers behind you as possible. If you did raise, it would be two bets for them to call and many would fold. Also, recall that on the turn the bet limit is doubling, so you may want to wait until then for a check-raise. This is a form of "slow-playing" or "sand-bagging". Basically you are disguising your hand, pretending it's weaker than it is, trying to get more people to stay in the pot and bet at it.
Let me briefly discuss the check-raise. The purpose of a check-raise is to disguise your hand so that people will get their money in the pot. You lead out with a check hoping someone will bet so you can raise. Their bet is now "trapped" in the pot, so at least you win that. I advise almost never check-raising. You just don't need to worry about this kind of play, and you're likely to get it wrong. Keep it simple, and your play will still seem erratic enough.
Similarly, slow-playing big hands should be done very rarely in Limit Hold'Em. The problem is that many hands are not as big as you think. If your hand is weak, you need to bet to make other people pay to draw. If you have something like two-pair, you better bet! Almost anything weaker than a low flush should be considered weak enough that you need to defend it by betting.
When slowplaying, it's important that your opponent is drawing to a hand that won't beat you. The whole point of slowplaying is to let your opponentcatch up enough that they will bet at you or call you bet (eg. put their chipsin the pot). So, first we assume they don't already having a good hand. If they did, you wouldn't slow play. If you do slow play, the whole point is thatyou *want* them to hit their draw, so if they are drawing at a hand that beatsyou, that's a disaster! The main case is when you have something like a set(three of a kind). If the board is rags, you might put them on having two overcards. So, they are drawing to make a pair. If they do make that pair, they will pay you off. Now, what if the board shows a two-flush and you think they don't have overs, or maybe the board shows straight-draw cards (like KT9 or something).Now, if they hit their hand, they beat you; if they don't hit, they'll just fold to a bet anyway. The only exception to this is that severe slow-playing against an aggressive player can induce bluffs. This is a risky play, but can pay off.
Mike Caro's notes on betting the river -
o Oftentimes you shouldn't bet a strong hand if your opponent bluffs too
much. You'll sometimes make more money by checking and letting him try
to bluff when he holds a weak hand.
o The more liberally your opponent calls, the more medium-strong hands
you should bet for value.
o If a player is threatening to call, you should bet all medium-strong
hands. When you see this, the player is trying to prevent your bet. That
means he's weak and looking for a cheap showdown, but will often call
reluctantly if you bet.
o You should not bet medium-strong hands into very tight players. You
won't get called by weak hands that you can beat, and are only likely to
lose when you get called.
Sklansky has a good section on all this in Theory of Poker. One thing I'd like to emphasize is that in practice, all the exact details of this are not that important. Generally you will be playing against someone who makes certain large mistakes that you can take advantage of, either they call too much or bluff too much, or don't bet enough, and you should tailor your play based on these mistakes. When considering river betting you have to consider -
1) basic best +EV play against an optimal opponent
2) adjusting your play based on your current opponent, taking advantage of their mistakes
3) bluff to possibly win the pot
4) vary your play for deception
One little secret of poker that people don't tell you is that it's ok if you make small semi-random mathematical mistakes, because that's just a form of deception and varying your play. Your opponent doesn't know exactly what kind of mistakes you're making, so they can't use it to play better against you.
Always in Poker you have to do a sort of Bayesian analysis. What cards do you estimate that he has, and how would he play them?
When someone checks into you on the river, they generally either have a very weak hand or a monster. If you have a moderate hand, you should just check it down. If you have junk, you might try bluffing it. If you have a monster, of course you bet.
Weak hands are best to just check down cheaply. If you bet with them, you are essentially just bluffing. That might be a good play if you smell that bluffing is a good move in your situation, but be aware that only good hands will call, so the fact that you have bottom pair or something like that doesn't make it a good bet. On the other hand, calling with something like bottom pair can be a good move if you feel like he is on a steal. The point is that your opponent is far more likely to put his chips in the middle with weak hands if he is betting, not calling. You have to think to yourself - "what hands do I beat", and then "how do I get him to put his chips in with hands that I beat?"