introduction to bet sizing
i had to write an article for a writing course that i'm taking at school, and figured i'd just post it here. comments/corrections/opinions/criticisms are welcome. oh, warning, this is long.
INTRODUCTION TO BET SIZING IN NO LIMIT HOLD’EM
Written by |~|yper
When it comes to writing poker strategy articles, bet sizing is often left out. Typically, people will tell you to bet big with big hands, and to bet small with small hands. This sounds reasonable, and certainly is highly effective at micro stakes, but once you start moving up to small stakes this becomes highly exploitable. Hence, bet sizing properly is essential to earning a respectable winrate.
Bet sizing is a very difficult topic to discuss clearly and concisely because it is closely related with almost all other aspects of playing no limit hold’em. Everything from position, hand ranges, pot size, and stack sizes must be taken into account to size your bets profitably. While each of those aspects can be discussed in great detail, bet sizing ultimately ties everything together.
Your goal for every hand is to maximize expectation. Bet sizing is all about controlling and manipulating the size of the pot, and if done properly, you can force your opponents into very difficult situations. To demonstrate, let’s walk through an example hand.
You are dealt AhKh on the cutoff, and everyone at the table has $100 stacks with $0.50/$1.00 blinds. It is folded to you, and you raise $4. The button, who is a solid player and not very tricky, reraises to $14. The blinds fold, and you decide to call and see a flop.
The pot on the flop is $29.50, and the cards fall Kc 4h 4s giving you top pair top kicker. Since the button is straightforward, you can reasonably expect that his range of hands that would reraise preflop to be heavily skewed towards high pairs and strong unpaired cards such as AK, AQ, and KQ. You are only behind two hands: aces and kings. Now that we have assigned a reasonable hand range for our opponent, our next step is to decide how to get money into the pot since our hand is very strong. We can expect our opponent to continuation bet a large majority of the time. Betting out is a bad option because it allows him to fold hands like JJ and TT, so we check. We run the risk of him checking behind, but that is unlikely because the flop is uncoordinated, and our opponent will expect us to fold to his bet every time unless we have a king or high pocket pair.
Our opponent bets $22, which is about 75% of the pot. We call because raising will fold all underpairs that he might have. The turn comes with As, which is the best card in the deck that could have fallen. It has improved our hand, but that is not important. This is a great card because it has improved our opponent’s range of hands. AQ and AJ just improved and now have showdown value. While the ace puts an extra scare card for underpairs such as JJ and TT, our call on the flop demonstrates strength, and if our opponent had one of these hands, he is unlikely to invest any more money into the pot. The ace also doesn’t improve our hand based on the hand range we assigned to our opponent. We were behind pocket aces and kings on the flop, and the ace on the turn does not change that.
We check again, allowing our opponent to bluff his underpairs, or value bet his pair of aces. To our delight, our opponent bets $30 into the $73.50 pot. We push the rest of our stack, which increases the pot size to $167.50, and it is $34 more for our opponent to call, which gives him 5:1 odds. Unfortunately for our opponent, we have put him in a very bad situation. He is losing almost every time he calls, and he knows this, except that the pot odds are too good to fold, and most players are unable to fold here even when they know they should. Our opponent calls, and flips over pocket kings, which means we were drawing dead the whole time. The river does not improve our hand.
Let’s look at this hand again with our roles reversed. The cut off raises $4, and we reraise to $14 with our kings on the button. The blinds fold, and our opponent calls, and the flop comes Kc 4h 4s. Again, we must assign a reasonable hand range for our opponent. Since our opponent is aggressive, he will raise most pairs, and strong off suit cards. This is a bad flop for us because we cannot get any value unless our opponent hit a pair of kings, and since we have two of them already, it is extremely unlikely. He checks. While it may seem reasonable to check behind and allow our opponent to improve their hand, this is incorrect. Our opponent knows we are aggressive, and if this is the one time we do not continuation bet, our opponent will pick up on that and be much more cautious. Not only that, if we check, we are manipulating the size of the pot. We are keeping it smaller, which will make it far easier for our opponent to fold their hand even if they do improve, because a raise on the turn is a dead giveaway that our hand is extremely strong. Since we should bet, we must decide how much to bet.
We need to bet an amount such that we can force our opponent into putting in the rest of his stack on later streets. The size of the pot on the flop is $29.50, which means both of us still have $86 more to bet. If we bet 50% and get called, the pot size on the turn would be roughly $50 with $71 behind us. If we bet 100%, the pot size on the turn would be $90, with $56 behind us.
If we bet the middle ground of 75%, the pot size becomes around $74, with each of us $64 behind. Once the size of the pot exceeds the size of your stack, any bet or call you make on the turn will likely put you all in before showdown. Even a weak 25% sized bet can force you all in. On the river, the pot size will be $112 (assuming our opponent called the $19 bet on the turn), with both of us having $45 behind. Pushing gives the other player roughly 3.5:1 odds, which means unless you were bluffing the whole time, you are probably calling. We bet $30, which is not weak, and not strong, and the rest is history.
In this example, both players were trying to trick their opponent into putting more money into the pot. Stack sizes were also straightforward, and with the reraised pot preflop, it was very simple for both players to get all in. Bet sizing in reality is much more complicated. Often you will be trying to get your opponent to put money in with a mediocre hand. Also, the example hand would have played out completely different if both players had $200 stacks instead of $100.
Nonetheless, it should be clear that understanding how bet sizes can affect the pot size on later streets is essential to exploiting your opponents for the maximum amount.
