Reasons why people bet the way they do

There are numerous reasons why people place bets. In order to be successful at poker, you need to consider not only what cards you are holding or the strength of your hand, but also how the hand has played out and what this player is trying to accomplish by making their bet. In order to get good at this, you need to observe not only how people play against you, but also how they play against other players. Donít let yourself ďzone outĒ just because you arenít in the hand anymore. Pay attention to how other people play and what other people are trying to accomplish whenever they place a bet. For instance, there are three main things people are trying to do when placing a bet.
First, someone might be trying to make you fold when they place their bet. If itís a small bet, then they are not trying to make you fold. Period. They are doing one of the other possible things shown below. If itís a large bet (3/4ths the size of the pot or more) or even an all-in then they may be trying to make you fold, but itís also possible they may be trying to get you to call in the hopes that they can build a pot they expect to win.
Secondly, they may be trying to get you to call in the hopes of building a pot they expect you to win. Typically when this happens someone is betting anywhere from 3-4 BBs all the way up to 1/2 the size of the pot. Now, even higher bets than that can be their way of trying to build a pot they expect to win. You need to be watching how they bet against other players to have a relatively good chance of knowing for sure.
One other reason someone may be betting is to prevent you from betting big yourself. If someone bets 1-2 BBs they are typically hoping you will just call so they can see another card. Again, itís possible they are trying to build the pot (you have to be watching their play to know for sure), but there is a good chance they just want to see another card and are hoping you donít reraise.
The morale of the story is, in order to know why people are betting you have to watch them not only when they play against you, but also when they are playing against other players.