The topic of using blockers when making decisions during the draw is one of the modern concepts of poker that came to the masses thanks to solvers, and this concept has evolved greatly over the past few years. If initially it was only about blockers to nuts and other strong combinations, now the blocker factor can influence the decisions of players in many situations, whether it is collating the opponent's continued bet, bluff ketching or all-in on the river at the right time. However, most players either do not pay attention to blockers or understand this concept incorrectly and do not know how to apply it correctly. We hope that this article will help our readers better understand this difficult but interesting topic.
1. The concept of blockers in poker
Blockers are cards in our hands that block possible combinations for the opponent at the current moment of distribution, as well as on subsequent streets.
The presence or absence of blockers is especially important in 3-bet sweats, on boards with a lot of draw, during the push-fold phase of the tournament and when trying to bluff. To successfully use the concept of blockers, it is important to be able to determine the range of the opponent's starting hands as accurately as possible.
Example of the impact of blockers on combinatorics
Suppose our villain opened from the middle position (MR) and we made a 3-bet from the button (BU). We will not specify our hand yet.
- To begin with, let's estimate the open-raise range of the enemy: 22+, A2s +, A9+, KJo, K9s +, Q9s+, 89s+.
Suppose that, faced with a 3-bet, the opponent continues to play (through a call or 4-bet) about half of the specified hands (99+, ATs+, AQo+, KTs +, QJs + 98s +), and the remaining hands prefer to fold. Thus, the fold equity after our 3bet is approximately 52%. Now let's see how the fold equity will change if we take into account the blockers in the hand with which we made the 3-bet, for example, the 
presence of a king and Queens reduces both the number of possible open-raise combinations of the opponent and narrows his range of protection, in which there will now be 50% less pocket ladies, pocket kings and KQs, and 25% less AQ+, QJs, KTs-KJs.
- Now the same open-raise range (22+, A2s+, A9o+, KJo+, K9s+, Q9s+, 89s +), but minus our blockers and, will be 8% fewer samples (combinations).
The range of protection after our 3bet will be reduced by 14% of samples from the total number of protection combinations. Then the fold equity at 3-bet with KQo will be 58.3%. Thus, the difference in the fold equity values was more than 6%. The presence of cards K and Q in the 3-beta narrowed the opponent's defense range more significantly than his open-raise range.
2. 4 main types of blockers in poker
Let's look at the main types of blockers and how they are used in a practical game.
Nuts blockers
The most obvious type of blockers are blockers to nut hands such as flush, full-house or straight.
- For example, the flop has three Diamonds ( for example,
), and we have in our hands 
Although we only have a flush draw, we know with 100% certainty that the opponent will never have a nuts here (unless the board allows you to collect a straight flush).
The presence of a blocker to nut flushes or straights (on an unpaired board) can be used, for example, for a very aggressive bluff in large banks, which can make an opponent defoliate even his strong hands, for example, a weak flush, if we manage to assure the opponent that we have a nuts flush. We do not recommend using this on microlimits. Suppose we defended on BB with
, and the flop 89Q came out (the suits are not important in this case). In this case, our presence reduces (blocks) the probability of the opponent finding a straight, since the number of JT combinations in the opponent decreases.
- Another example: Our bluff with the "dead" dopper 67s on the board 267-2 in order to knock out the over pair 88+ will be more profitable than with a usual empty hand, since we reduce the likelihood of full houses for the opponent on pocket pairs 66 and 77 .
Velha blockers value
Blockers to other, not nutritional, but strong hands of the opponent, such as set, or two pair, or TP with a good kicker.
- Let's say:
And we are betting on c-bet by an opponent with EP villain. It would seem to be an ordinary situation where we simply did not get into the board, but in fact we have a good check-raise to bluff as a bluff with blockers.
- Firstly, we have a blocker on the opponent's AQ and AK, and these are the hands that we can't beat with a bluff.
- And secondly, we have overcards to his 77-JJ underpairs, and in the case of his call (after our check-raise), we have the equity to get to the best combination. For example, with the hand 9, then we would not have such advantages in bluffing.
Another example. We have 
a hand on the BB, and we defended against the rise with Co. The flop came out 
. The presence in our hand reduces the likelihood of dopers K7 and 78 in the opponent, and also reduces the number of sets by 77. All this will have a beneficial effect on the fold equity in the case of our bluff-raise, since these strong hands villain clearly would not fold. In addition to increasing the fold equity due to blockers, we also increase the equity potential of the hand. During the bluff with 79, we have a chance to get to the trips of sevens or in two pair with a nine. That is why the bluff with the 3rd pair is mandatory on many types of board.
Blockers for bluff
Blockers on the bluff are cards that block a certain part of the opponent's bluff range, which allows us to assume the value of the opponent with a higher probability.
- For example, we defended
on the big blind and on the board:
without flush draw, the opponent put 2 barrels, and puts the 3rd time on the river.
Although our hand looks decent, it is a bad card for us, since it blocks a large number of semi-bluffs (QJ, KJ, J8) with which the opponent could barrel. In this case, we would prefer to have T with a lower kicker, which would not block the opponent's bluff, for example, T4s. This example is very illustrative. When we want to catch the opponent's bluff, we most of all pay attention to his desire to play aggressively straight draw and flush draw combinations. Therefore, blockers to this part of its range are easily visible and can give us an additional reason to make a pass fold. Conversely, if we do not have blockers to his bluffs in this distribution, but on the contrary the blocker to his vellum (KTo hand, which reduces the likelihood of AK in the opponent), we tend to lay the bluff to the opponent a little more often, and the decision to open it will be more reasonable.
3. How the concept of preflop blockers is used
We have already told a little at the beginning of the article about how a blocker can affect the fold equity of our 3bet on preflop. In this section, we will continue the preflop theme and tell you how you can use this theme.
Anti-stiling protection
Stealing blinds from late positions is a common technique that is often used by players at all limits. Protection of blinds from styling can be both passive (via call) and active (via 3-bet). The presence of blockers on the blinds to the velle range of the open raiser (usually A or K) can be an occasion for active protection of the blinds through 3-bet, since the hands of Ah or Kh (especially offsuited) have poor playability on the post-flop. This assumption is not supported by practice when analyzing the database of middle and high limits, although it works perfectly at low limits. Ah and Kh hands played in the polar bluff protection through 3-bet worse than hands without blockers, besides offsuited A2-A6 showed the best winrate through cold-call. K2o-K5o is still better played through 3-bet, but their winrate is worse than that of 3bet with garbage hands without blockers.
The answer to this riddle is:
- In 3-betpot without a position with small Ah and Kh, we often fall under the dominate in the top pair, since these hands are widely included in the range of protection of competent players. For example, an opponent can protectA9o + and K7s+, which is wider than the average protection for low-limit players.
- In the middle and high competent players from late positions, attacking the big blind, are very active in bluffing as a bluff in Ah and Kh board, thereby giving our top pairs excellent pot control and bluffing. Low-limit players bluff less and thus pay less for these hands if they play them through a cold-call.
Blockers when playing 4-beta in a bluff as a bluff
Along with active styling, 3-bets on the extended range have also long been included in the arsenal of many players professing an aggressive style of poker. In case we opened and got 3-bet, having high cards in our hand (A, K, sometimes Q) gives us blockers to the vellum range of 3-betor, which allows us to consider the possibility of 4-bet in a bluff as a bluff. At the same time, it is important to remember that this technique can be used only against players with a high 3bet score (8% or more) and only against standard 3bet sizing. High blockers (A, K, Q) increase our fold equity, which is easy to calculate, but also give us a chance to win the pot on post-flop in the case of an opponent's call in 4-bet pot. Hands Ah and Kh can give us a high pair, and an opponent with TT-QQ, who decided not to shove against 4-beta, will have to give us a pot.
All-in or call all-in
Quite often you can see situations when in the push-fold stage players put all-in or accept it with rather marginal hands, such as weak connectors or just small cards. Here we can talk about a variation of the theory of blockers, which can be conditionally called the concept of “living cards”. The calculation is made on the fact that usually all-in is placed (or accepted) with sufficiently strong hands: Ah or Broadway cards. Small cards do not have blockers to such a range, which means they will remain “alive”, trying to collect a pair and win without falling under the dominate. The disadvantage of this technique is the frank weakness of low cards (connectors, etc.) against over pairs.
4. Application of blockers on post-flop
Earlier in this article, we have already provided many examples of how blockers can affect post-flop solutions. In this section, we will provide some additional examples to reinforce this topic.
Rectilinear value collection and fine collecting of value
In a situation where we have a nuts (for example, a set) or a strong hand (over-pair), but do not block the opponent's velly range, we should lean more towards large additional bets. On the contrary, if we block the opponent's vellya hands, we need to think about more subtle bets to allow the opponent to start paying on middle hands. The pot will grow, and at the same time the likelihood of an opponent making a mistake will increase.
- For example, we have
, and we reach the river on the board:
without flush draw, that is, we have a nut hand. However, the structure of the board is such that it will be difficult for an opponent to call a large bet if he does not have a 7. Therefore, it is necessary to choose the size of the bet that the opponent would pay with Kx or 2 pairs.
But most often this concept uses the factor of top pair brokers. If we have a strong hand, and we do not block the top pair of the board, it is much easier to get the extract value than if we block the top pair (for example, with the top set). Because the main hand at the the long run, which pays us a vellya, is a top pair.
Making a decision on the collating of the opponent's barrels
When we think about a complex call, it is worth remembering about blockers.
The general rule is that the presence of blockers to the opponent's velle range increases the number of bluff (example 1). Conversely, the presence of blockers to the opponent's bluff increases the frequency of the velly in his value (example 2).
- Example 1
The villain made a c-bet and puts the 2nd barrel. In this situation, we have a good blocker to the opponent's velly range -
is
that which blocks the vellya hands AA and AQ. But the hands with which the opponent will continue to barrel with a semi-bluff, we do not block at all: KT, JT, T8, KJ, 78, that is, any gatshots and straight draw. In a situation where we partially block the opponent's vellya range, and do not block the bluff range at all, a good solution is to make a call.- Example 2
Villain puts
a counter-bet. in our hand is a blocker to a big part of the opponent's range, with which he will bluff, having equity. These are starting hands like T9, QT, sometimes T7. Thus, the frequency of bluff in the opponent's range decreases, and we must be on our guard: barreling in such a situation will contain a large number of vellus. Of course, we will not throw it on the first bet and it will not be easy to throw it even on the second, but in general we are already looking at the situation, and on the river we will definitely throw it on the 3rd barrel even into absolutely blank runouts.Capture initiative - Blocker-based bluff
In certain situations (especially with blockers on nuts combinations), strong pressure can be exerted on the opponent, forcing him to throw off strong hands.
- We are on BB and defended against the raise with UTG with a hand
- On the flop,
we wait, the preflop aggressor puts a counter-bet c-bet. - We have the 2nd pair and a backdoor flush draw. Raising in such a situation does not make sense, and we just call.
- Turn
We are a check, an opponent is a check. - River
We are a check, the opponent is betting big.
who came on the river is very suitable for the pre-flop-raiser range from UTG and seems to incline us to a fast fold. However, the factor of blockers comes into play here:
in our hand, it blocks the nut combination QJ and reduces its probability in the preflop aggressor. But we may well have QJ, and our draw line for this hand is quite consistent. Therefore, our check-raise - all-in - will put the enemy in a very difficult position. Even if he put such hands on the vellya as AK or KJ and sometimes even a doper on K9, it will still be extremely difficult for him to make a call with these hands. Also, the absence of 99, TT, QC and 44 sets in its range plays into our hands, since we are sure that on the shotboard on the turn the villain would definitely put them on the velly and for protection value. There are prerequisites for a very high-quality, chic all-in bluff as a bluff! But be careful with such actions at low limits, sometimes opponents tend to call completely unwisely, because they risk only a small buy-in. IMPORTANT: When you are bluffing based on blockers, the size of your bet should be large enough to maximize fold equity. You need to use the same sizing as if you actually had nuts. It is also desirable that you block the opponent on chips, so it will be more difficult for him to decide on a call, and you will have at least a few chips left for promotion in case of defeat.
- Another example, we have , and we find ourselves on the river with open cards:
The opponent made a bet on the flop, a check-check was played on the turn, and he puts it again on the river. We block JT (nuts straight), and here it is quite likely. Therefore, sometimes it is worth a big cut to knock out Q and even A from the enemy.
5. Conclusion
The concept of blockers has long been an integral part of poker and is actively used by professional players to make the most effective decisions on preflop and postflop. However, this happens primarily at high stakes, where players are forced to hone their game to the smallest detail and join the fight at different levels of thinking in order to adequately compete with the strongest of rivals. It is not necessary to use the brokers factor at a low limit, however, it is useful to study this topic to increase the skill of your poker theory.
Blockers help in making decisions, but it is necessary to take into account other factors: the opponent's style of play, his range, the draw line.
Always remember that the broker factor is not in itself a key factor in the decision. This is an additional factor, one might say - a corrective factor. It only increases or decreases the assumptions that you should already have about some distribution, but does not create them, based only on the blocker factor.
