And why to bet?
One of the difficulties of No-Limit poker games versus Limit games is to know how to choose the size of your bets and how to interpret bet sizes of your opponents' bets.
Pre flop, it is commonly agreed by poker experts that a good bet size should range between 3 BB & 5 BB in ring games, and 2 & 3 BB in tournaments.
Tournament bets should be smaller than cash games, because you want to protect your survival and not risk your entire stack lightly. Controlling the initial betting limits the chance to reach huge pots by the river.
It is recommended to make pre flop raises of 3 BB at the beginning of the tournament when stacks are the deepest, lowering that to 2.5BB and then to 2BB when the M ratio decreases, i.e. when the stacks get small compared to the blinds.
On the other hand in deep-stacked ring games, there is no risk of survival in consideration and betting from 3 to 5 BB is ok in 100BB stacks or even in 50BB stack situations. Clearly if you play a short stack strategy like 20BB, then this is a push or fold strategy and there is no need to think about bet size.
How you decide which to choose is critical. Some transparent players make larger bets for their better hands and smaller bets for their weaker ones, and this is obviously like "telegraphing" the strength of their hands. Avoid being predictable and do not follow such simple technique.
A better approach is to bet larger when you are in early position than in late position such as the button. The reason is that if you have the disadvantage to be out of position, you want to increase the chance to make weak hands fold behind you and reduce the number of players in the pot.
In late position, there is not need to invest as many chips in the pot, as you are glad to be called by the blinds and to play the hand in position. Note that the strength of your hole cards in not the important factor to choose the size of your bets, but your position is.
Things get much more complicated post flop, obviously.
For the first player to bet at the flop, the options are traditionally pot, half pot, 3/4 pot and over-bet.
Unraised pots are rare, so the pot is normally at least 6BB or more. Pot sized bets are large bets representing big hands. If one player calls, the pot will be three times the size of the flop pot by the turn and even bigger by the river.
This is the exponential effect of bets as the streets progress in a hand. If you make such a bet size, know that this may lead to large pots by the river. This is why a more natural bet size at the flop is around 60-70% of pot size. It achieves nearly the same result as a pot-sized bet, without committing too many chips.
Smaller bets are possible such as 1/3 of pot. These are so-called blocking bets, designed to induce your opponent to call a smaller bet than the size of the bet he would make normally. So you have put fewer chips in the pot. If he raises, then you know that you are beaten and you can muck.
Such blocking bets can be used as traps to induce a raise. If you notice that your opponent likes to apply pressure by attacking weak bets and constantly forcing people into difficult decisions, then a well-timed blocking bet can be used to trap him and induce him to raise when you have a monster hand.
Conversely, oversized bets such as 1.5 or 2 times the size of the pot are rarely observed. This is an unnecessary and risky tactic. There is not need to bet so much to protect your hands and this is just an invitation to get raised whenever someone has a real hand.
Beyond the flop, the logic is to apply the same bet size compared to the pot, but as the pots are bigger, lean toward the smaller size such as 50% of even less. If more than 50% is wagered, this is normally reserved for very big hands, and depending on the stacks, it can easily lead to all in situations.
Be cognizant of how your bet sizes affect the risk that you take and always know why you choose your bet size. You can try the largest online poker room pokerstars to practice your bet size.