Semi-Bluffs for Advanced Players

Introduction

In this article:

• Different forms of semi-bluffs
  
• Important factors for effective semi-bluffs
• The math behind semi-bluffs

As poker has grown in popularity, so has the general aggressiveness in small and mid-stakes games. Good poker players do not ignore the advantages of being aggressive, nor do they ignore the chance to exploit the weakness of other players. Many casual players will have seen a wide range of moves made by opponents. Often times, these moves appear extremely creative and might give the casual player the courage to try something similar. They are, however, usually soundly based on the concept of "semi-bluffing."

This article is designed to provide a comprehensive basis for understanding what semi-bluffs are and how/when they can be played. Instead of making clueless and incorrect decisions in an attempt to look like a pro, you will know which factors to look for when considering such a move.

What is a semi-bluff?

You obviously need to know what a semi-bluff is before we get started. We'll start with a brief definition:

A semi-bluff is nothing more than an aggressive move made with a hand that is probably behind at the moment, has the chance to improve on later streets.

You semi-bluff when you bet/raise with a weaker hand that still has a certain amount of pot equity. There are two ways to win the pot with a semi-bluff.

• A semi-bluff can force an opponent to fold the better hand.
• You improve your hand by catching an out and win at the showdown.

A semi-bluff cannot be made on the river, since you won't have any pot equity and there won't be any more cards that can improve your hand. Most semi-bluffs are made on the flop, but some players semi-bluff the turn as well.

You should also only semi-bluff when you have a decent amount of pot equity (the higher your pot equity, the better your chances with Plan B). In a best case scenario, your opponent will simply fold to your bet/raise. This is always Plan A, since you almost certainly hold the worst hand at the moment.

Plan B looks like this:

You hit an out and now have the best hand.

Two kinds of semi-bluffs

There are basically two kinds of semi-bluffs: The all-in semi-bluff and the non-all-in semi-bluff.

You basically move all-in to limit the action on later streets. This can be a 4-bet push with Axs before the flop or with a strong draw on the flop.

The advantage of going all-in: you maximize the equity of your drawing hand.

Going all-in also prevents "action killers" from robbing you of a pay off on a later street. If you play a nut flush draw passively and suddenly bet when it completes, you will make it easier for your opponent to lay down a good hand.

Going all-in not only forces a tough decision on your opponent, but can also maximize your equity.

With this form of the semi-bluff, you do not put your whole stack at risk. A mathematical analysis shows that you need to generate more fold equity when you make larger bets in order to semi-bluff profitably.

There are many situations in which a larger bet does not generate significantly more fold equity than a normal sized bet. A smaller sized semi-bluff on the flop is often enough and can even generate more fold equity than an all-in push.

Another reason to use the non-all-in semi-bluff is to gather more information based on the response of your opponent. This allows you to make a better decision later and not end up all-in as an underdog.

Not going all-in also allows you to balance your value bets with semi-bluffs, which will improve your post-flop game. You also have to consider that thinking opponents will be able to deduce your hand quite easily if you push directly. Since you would generally not overbet the flop with a strong hand like a set, your overbet will look like a draw that is afraid of getting called.

This disadvantage of not pushing all-in is, of course, the possibility of the board texture changing dramatically. You could also face more experienced opponents who know how to make the right move to shake your confidence when you're in a big pot.

What is the purpose of a semi-bluff?

Since we now know what a semi-bluff is and what basic conditions must be met in order to semi-bluff, it's time to address the exact goals/purpose of a semi-bluff and how to best execute a semi-bluff.

Semi-bluffs accomplish several things simultaneously. Although you may have a particular objective in mind, in the long-term, semi-bluffing is not limited to a single goal.

Through the act of betting or raising, you are applying pressure on your opponent and forcing a decision to be made, which often depends on a combination of his hand strength and internal feelings. You may very well underestimate the pressure you can exercise by betting and/or raising.

For example, when you execute a non-all-in semi-bluff, you are not only confronting your opponent with the current bet amount, but you also leave him in the dark about the possibility of larger bets on later streets.

Good players will try to assess the playability of a given hand and plan ahead. Many of them will tend to fold the best hand when confronted with a bet/raise.

You will start winning a higher percentage of the pots you play for once you integrate the semi-bluff into your game. Your opponent gives up a significant amount of pot equity by folding, since his range is usually made up of hands that have you beat at the moment.

Semi-bluffs are also a way of balancing your own hand range. Better opponents are, quite simply, better able to put you on a range of hands. Obviously, an opponent who knows exactly what hands are in your range when you play a given line will adapt to play perfectly against you.

You can polarize your range by adding semi-bluffs to your repertoire, which also gives you a certain element of surprise. You will lose against opponents who always know what range you are on, since they will hardly ever make a mistake against you. Mix things up a bit.

Let's take a look at a simple of example of why balancing is so important and examine your range for 4-betting before the flop with a 100 BB stack.

You can put your opponent on QQ+, AK after a 4-bet in the lower limits. Making the correct decision is easy enough once you compare your equity to the pot odds.

You can, however, polarise your range for a perfect '4-bet defense' by 4-betting with hands like suited connectors that you can easily fold to a 5-bet.

Semi-bluffs allow you to play with a wider hand range after the flop, which makes it harder for your opponent to fold to your value bets and call your bluffs. You also get more value for your strong hands.

Opponents will respect your bets/raises when you have a tight, solid image. This means you almost always generate enough fold equity to semi-bluff profitably.

You can also use semi-bluffs as a means to alter your table image for a session. Several quick semi-bluffs can create a loose table image, which you can then use to your advantage by tightening up later.

These are just a few reasons why semi-bluffs should be a part of your game. There is, however, another aspect of the game in which semi-bluffs play a central role: the game flow.

It's a matter of taking advantage of the flow of the game and entails more than just table image and the other aspects we have already mentioned. You want to pool all the known information you have to analyze a hand as objectively as possible. Ask yourself the following questions:

• Are any opponents on tilt?
• How have the last hands been played?
• What is the game speed at the table?
• Has a player indicated he would like to leave the table soon?
• Is there a new player at the table?
• Does any player currently have momentum?
• Do you have any gut feelings about the table or a specific opponent?

This all may sound a bit abstract, but you will, as you gain experience, start to get a feel for the situation at hand, for example, when an opponent is weak or when you can make a profitable semi-bluff (even spread over several streets).

Understanding the flow of the game and being able to take advantage of the situation at hand should be a top priority. Incorporating semi-bluffs into your game successfully will separate you from the rest of the pack.

What should you look out for when semi-bluffing?

You need to have a plan and a set goal in mind in order to execute a semi-bluff profitably. It's important to know why you are making a certain decision and how that decision will affect the hand. The following factors need to be taken into account when making your decision: fold equity, SPR, the playability of your hand, and all the reads and information you have accumulated so far.

The term 'fold equity' refers to the probability that your opponent will fold his hand. This is a very important part of semi-bluffing, because it is the factor that determines if you can win the pot directly and without a showdown. As you may suspect, the higher the fold equity generated, the more profitable your semi-bluffs will be.

Although you cannot concretely define the fold equity you generate, there are certain variables that have an effect.

You are able to generate more fold equity when the pot is currently small and your opponent's remaining stack is large. Your opponent will be afraid that he won't be able to see the showdown despite calling and will often fold his hand.

The fold equity you generate on different boards depends heavily on the opponent you are facing.

You can generate a lot of fold equity against some opponents on a draw heavy board, while others will suspect that you are on a draw and put their money in with marginal hands.

Similar considerations must also be made on dry boards. Some players will fold a lot, simply because your aggressive playing style can only indicate a made hand. Other players, however, will know that there aren't very many hands you can play so aggressively on a dry board. Thus, these players will let you re-bluff and transform their made hand into a 'bluff catcher'.

An important aspect, as always, is your relative position at the table. When you are in position, you will be able to generate more fold equity, since your opponent will not always want to continue playing for a large pot with a mediocre hand out of position. You can, therefore, expect opponents to fold more often to semi-bluffs made in position.

Before you semi-bluff check/raise out of position, you need to know which turn cards will slow you down and which ones will keep you on the gas pedal. Your opponent will quite often call your check/raise with a good hand so that he can then call more bluff bets. You need a good frequency of value bets vs. semi-bluffs or you will end up bluffing too often and having to check/fold on the turn.

The amount of fold equity you need to generate in order to commit yourself with a semi-bluff depends on your stack : pot ratio. This is an important aspect when deciding whether or not to make an all-in semi-bluff.

One thing you should always bear in mind: When you are semi-bluffing, your opponent will almost always have more than 50% of the pot equity. For you, this means the larger your stack size, the more you lose when you get called.

Depending on the fold equity you can generate, you will still be able to make +EV semi-bluffs. You just need to remember that with a high SPR, you should look for situations in which you have high fold equity and a decent amount of pot equity against your opponent's range.

As we said before, Plan A is winning the pot directly. This, of course, doesn't always happen, which is why you have a Plan B. This is where the board texture and quality of your hand become even more important. If have haven't balanced your lines previously and your opponents can tell what kind of hand you are on, you won't be able to count on implied odds, either.

An example of an all too transparent line that won't get paid off: You play 'raise flop, check behind turn, raise river' with a flush draw that completed on the river. It's too obvious that you semi-bluffed with the flush draw on the flop and just completed.

The board texture can have another effect on the hand: It is better to refrain from semi-bluffing when there are a number of possible turn cards that would make your hand unplayable. You will often end up having to fold a hand with decent equity when your opponent calls and one of these cards show up on the turn.

Your semi-bluffs will become more effective as you learn to make reads on your opponents. Try to tailor your play to the opponent at hand. A semi-bluff against a calling station or a maniac will obviously be less profitable than a semi-bluff against a weak, tight opponent.

The math behind the semi-bluff

In order to get a better feeling for when a semi-bluff will be profitable, it's important to understand the math behind the semi-bluff. This, in short, means calculating the EV of all possible actions to make the best possible decision.

You will now see the factors behind the EV of a semi-bluff and how it differs from a pure bluff.

You should be familiar with the basic EV formula for aggressive moves. Here is how you calculate the EV of a semi-bluff:

EV(semi-bluff) = Fold Equity * Dead Money + (1- Fold Equity) * [Equity * (Dead Money + Bet Size) - (1- Equity) * Bet Size]

This formula calculates the EV of your bet or raise on a single street (and is perfect for all-in semi-bluffs). There are a few finer aspects to pay attention to when making a non-all-in bluff.

The problem is creating a mathematical model that takes the playability of your hand and possible changes to the board texture into account. Looking at our formula, however, shows us the most important factors:

• Fold equity
• Dead money -> pot size
• Equity vs. opponent's calling range
• (Semi-bluff) bet size

Look at how the formula changes when you make a pure bluff on the river (meaning you have 0 equity against your opponent's calling range):

EV(Pure Bluff) = Fold Equity * Dead Money + (1- Fold equity) * [0 * (Dead Money + Bet Size) - (1- 0) * Bet Size]

EV(Pure Bluff) = Fold Equity * Dead Money - (1- Fold Equity) * Bet Size

The profitability of a pure bluff is derived solely from the fold equity you generate. With a pure bluff, the long-term profitability comes entirely from the fold equity you generate. You need to pay closer attention to the risk : cost ratio.

• Fold Equity : f
• Dead Money: d
• Equity vs. Opponent's Calling Hand Range: E
• Bet Size: b

So what is more important when semi-bluffing, getting your opponent to fold or trying to maximize your equity against your opponent's calling range?

The key to balancing these two goals is the ration between your bet size and the amount of dead money in the pot.

The larger the bet size: dead money ratio, the greater your fold equity and the lesser your equity against your opponent's calling range.

If, for example, you want to maximize your equity against your opponent's calling range, you should refrain from betting/raising. This, of course, would mean not semi-bluffing.

Equally important in answering this question is knowing the possible values for e and f. Your equity will always be less than 0.5 when semi-bluffing, since you would be value betting with more than 50% equity.

Your fold equity will be between 0 and 1, since your opponent could either fold or call with his entire range

• 0 < E < 0.5
• 0 < f < 1

If you play around with the formula a little bit, you can see that you can increase your fold equity by increasing your bet size. You cannot, however, change do anything to change your equity. Keep in mind that your equity with a drawing hand is usually the same against a weak made hand and a strong made hand.

We now have the answer to our question: Try to increase your fold equity with larger bets when semi-bluffing. Your equity will not decrease significantly enough against a tight calling range to negate this advantage.

Keep in mind that this answer is purely based on mathematics and does not take the other factors/goals of a semi-bluff into account.

We can therefore mathematically prove our claim that:

EV(semi-bluff) = f * d + (1-f) * [E *(d+b) - (1-E) * b]

EV(f) = (d-Ed-2Eb+b) * f + (Ep+2Eb+b)

This linear equation can be graphically shown as a straight line with a slope of m=( d-Ed-2Eb+b), the Y-intercept of c=( Ep+2Eb+b) and the independent variable f. We will now try to disprove our claim. If we cannot succeed in doing so, we will know that we were correct.

To be disproven: EV(f+x) >EV(f) when x > 0 is

This will be disproven if the slope reaches a negative value. Therefore, d-Ed-2Eb+b must be < 0

When transformed, we obtain the following inequation:

d -E(d+2b)+b < 0

d+b < E(d+2b)

We can therefore say:

d > 0, b > 0, 0 < E < 0.5

Now we simply insert the extremal values for E and try to discern whether the condition can apply for certain values of d and b.

E = 0

d+b < 0

This can never occur for the case of d > 0 and b > 0.

E = 0.5

d+b < 0.5(d+2b)

d+b < 0.5d +b

0.5d < 0

This can also never occur for the case of d > 0.

Our claim must be correct, since the slope never reaches a negative value.

Example Hands

Hero $200
BU $112

1$/2$ No-Limit Hold'em (6 handed)

Pre-flop: Hero is Big Blind with K, Q
3 folds, BU raises to $7, SB folds, Hero calls.

Flop: (15$) 9 , 5 , 3
Hero checks, BU bets $12, Hero raises to $193 (All-In)

In this hand, you are playing OOP and flop a flush draw + two overcards + backdoor straight draw. This gives you at least 46% equity on average, even when facing an overpair.

You could check and hope for a free card or try taking the initiative on the turn even if you don't hit. You could check/raise (also a semi-bluff) if he makes a standard contibet instead of checking behind. The question is, how large should your raise be? Your opponent entered the hand with a little more than 55 BBs. A solid raise on his contibet would commit you to the hand; you would have to put the rest in on the turn, since your draw is too strong to fold.

Many players are inclined to push all-in on the flop in such a situation, since the equity of their drawing hand is currently at its highest. An all-in push also generates an enormous amount of fold equity. The decision whether to simply push all-in with such a strong draw decision ultimately depends on the opponent you are facing.

Remember what we said before: You would never push all-in with a set in this situation, which makes your move fairly transparent. You should also be aware of the number of turn cards that could slow you down (in this example there aren't many). There is, therefore, no reason not to simply raise. This keeps your range balanced and reduces the transparency of your hand.

The other question, of course, is how much fold equity you can really generate by pushing all-in. Good opponents will know you are on a draw when you do and be more willing to call with more marginal made hands.

Another reason to check/raise instead of pushing: A normal raise gives your opponent the chance to push with a weaker draw (which would give you much better equity against his range).

Pushing with this large of a stack is not necessarily the best way to semi-bluff.

Pay attention to your opponents and their playing styles and be aware of what you are trying to accomplish with your semi-bluff.

Hero $200
BB $200

1$/2$ No-Limit Hold'em (6 handed)

Pre-flop: Hero is CO with T , 9
2 folds, Hero raises to $7, 2 folds, BB calls.

Flop: (15$) K , J , 8
BB checks, Hero bets $12, BB calls.

Turn: (39$) 2
BB checks, Hero bets $25

You decide to fire a 2nd barrel after your standard contibet on the flop gets called. This may look like a good spot for a semi-bluff, but it's not.

Although you do have a very good draw and generate even more fold equity with a 2nd bet on the turn, there is simply no need to semi-bluff in this example.

You may be robbing yourself of the chance of seeing the river for a decent price by firing your 2nd barrel. But what are you going to do if your opponent check/raises? Checking behind is a better option, since you don't want to have to fold such a strong draw.

If you had a hand like A 9 on this board and your contibet got called, you would also be better off checking behind and calling a small bet on the river when facing an aggressive opponent, since they will often bluff with busted draws after you check behind.

Hero $200
BB $95

1$/2$ No-Limit Hold'em (6 handed)

Pre-flop: Hero is CO with J , T
2 folds, Hero raises to $7, 2 folds, BB calls.

Flop: (15$) 9 , 8 , 2
BB bets $10, Hero raises to $32

Your opponent unexpectedly donks into you on the flop. Your OESD + overcards is too good to fold. The question is, should you call (you have the right implied odds) or semi-bluff?

Before you continue reading, try answering this question for yourself. Think about the different aspects we've discussed so far.

If you think semi-bluffing is the best way to proceed, take another look at the stack sizes. Your opponent only had $95 at the start of the hand. But what if he pushes all-in? Would you call?

You would be getting 2.41:1 odds and could therefore make a +EV call with 29.3% or more equity. You will therefore be committed to the pot, and even if you generate enough fold equity to keep your opponent from going all-in on the flop all too often, you will still see yourself going broke on the flop as a big underdog quite often.

You keep a number of options open by simply calling. You could try floating on a lot of possible scare cards on the turn, or hit an out for a pair and feel more comfortable about investing more.

The point of this example was to show you that semi-bluffing on the flop isn't always the best option with such large stacks in play.

Hero $290
SB $250 good Regular
BU $200 TAG fish

1$/2$ No-Limit Hold'em (6 handed)

Pre-flop: Hero is Big Blind with A , 7
3 folds, BU raises to $7, SB reraises to $25, Hero reraises to $64

This is going to look a bit strange at first, since you see yourself 4-betting with a hand you would fold in a typical "blind defense" situation, even if the SB had folded.

This is one of those spots where metapoker comes into play. You will learn to spot them as you gain more and more experience. The BU has a wide open raising range and is probably trying to steal the blinds. The SB, a good player and regular at this limit, knows this and decided to actively defend his blind out of position.

As a very good player always trying to improve his game, you recognize this and know that neither player necessarily has a very good hand. You are also 130 BBs deep against a very good regular.

You decide to 4-bet against these players for the following reasons:

• The BU will often fold.
• The SB will also only be able to stay in the hand with a very good hand (due to the stack sizes).
• You can collect a fair amount of dead money often enough, since you generate high fold equity.
• You want to balance your hand range, so that opponents won't always know you have QQ+, AK in such situations.
• The 'card removal effect' is in place, meaning it is less likely that an opponent has AA or AK, since you have one of the four aces.
• You can easily get out of the way if an opponent does 5-bet.

As you can see, there are a number of good reasons for 4-betting in this example. This obviously not a standard move you should incorporate into your game and was only made due to the specific reads and situation at hand (stack sizes, positions, etc.). You won't find yourself in such a situation very often.

This example should simply should that you shouldn't click on 'Auto-fold' every time the BU open raises. You would have missed out on $30 in this example.

Conclusion

This article introduced you to some of the finer aspects of semi-bluffs. Always take the time to consider your options and know what you want to achieve with your actions:

• Semi-bluffs always have at least one goal.
• The most important component of a semi-bluff is the fold equity you generate.
• You can analyze the profitability of your semi-bluffs mathematically (esp. all-in semi-bluffs).

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