Lecture 53 [Advanced] Using Blockers

A blocker is a concept where the cards you hold physically limit specific hand combinations of your opponent.

Basic Strategy

Based on a 100BB stack in a cash game, blockers are crucially utilized in river bluff/bluff-catcher decisions, turn semi-bluff selections, and preflop 3-bet bluff construction.

Using Blockers for Bluffs: You bluff while holding cards that block your opponent's strong hands. For example, if you bluff on a flush board holding A♠, your opponent's probability of holding the nut flush decreases.

For Bluff-Catchers: If you hold cards that block your opponent's bluffs, you reduce your call frequency. If you hold K♥, your opponent's probability of bluffing with KQ decreases, which can lower your call EV.

3-bet Bluffs: Ax suited, suited Broadways (KQs, QJs) are good bluff candidates because they block your opponent's AK, AQ.

There are three reasons to use these strategies:

• Blockers physically reduce your opponent's hand combinations, changing probabilities.
• Blockers can play a decisive role in marginal bluff/bluff-catcher decisions on the river.
• When constructing a 3-bet bluff range, it allows for exploitation while maintaining balance.

Responses by Situation

1. Using Blockers When Deciding to Bluff on the River

When a flush or straight completes on the board and you have air, increase your bluff frequency if you hold key cards of the nut hand (A, K). Your opponent's probability of holding the nuts decreases, increasing your bluff success rate.

2. When Deciding on a Bluff-Catcher on the River

When your opponent makes a large bet and you hold a middle hand (two pair, top pair good kicker), increase your fold frequency if you hold cards that block your opponent's possible bluff hands. Your opponent's probability of bluffing decreases, which can lower your call EV.

3. Using Blockers for Semi-Bluffs on the Turn

When you hold a draw, increase your bet frequency if you hold a key card of the nut draw (A♠ in a flush draw). Your opponent's probability of holding a strong made hand decreases, and even if the draw misses, a river bluff opportunity arises.

4. When Constructing a 3-bet Bluff

Hands like ATs, A5s, KQs are good 3-bet bluff candidates because they block your opponent's premium 3-bet call range (AK, AQ, KQs). Your opponent's probability of 4-betting decreases, and their fold frequency increases.

Things to Consider

When deciding on a bluff or bluff-catcher on the river, try to think in this order:

1. What hands of my opponent do my cards block? Do they block nut hands? Do they block bluffs?
2. What hand combinations can my opponent have in this spot? What is the approximate ratio of their value range to their bluff range?
3. Do the hands I block constitute a significant portion of my opponent's range? Is the blocker effect large? Or small?
4. Does the EV of bluffing or calling change when considering blockers? What is the comparison of expected value with and without blockers?
5. What is the action choice? Make the final decision among bluff, call, or fold based on blockers.

Example Hand Analysis

Example 1: Using Blockers for a River Bluff

Game: Cash game 1/2, Stack 200BB
Position: Button
Preflop: Button raises $6, Big Blind calls
Flop: K♠9♠4♦, Pot $13, BB checks, Button bets $8, BB calls
Turn: 2♣, Pot $29, BB checks, Button checks
River: 7♠, Pot $29, BB checks
Hero Hand: A♠6♥

Thought Process:

1. “Who has a structural advantage on this board?”
   → A flush completed on the river, and the Button holding A♠ blocks the opponent's nut flush (including A♠).
2. “What role does my hand play within my range?”
   → A♠ is air, but it blocks the highest flush card, making it a good bluff candidate.
3. “Does my opponent have enough hands to fold / do they call often?”
   → The opponent is likely to hold Kx or a weak flush, and the A♠ blocker reduces the probability of a nut flush.

Conclusion: River bet $20 (2/3 pot)

Comment: Holding A♠ lowers the opponent's probability of holding the nut flush, increasing the bluff's success rate. The bluff EV may be higher than with air without a blocker (e.g., Q♦J♦).

Example 2: Reverse Blocker in a Bluff-Catcher Spot

Game: Cash game 1/2, Stack 200BB
Position: Big Blind
Preflop: Button raises $6, BB calls
Flop: Q♥T♠5♦, Pot $13, BB checks, Button bets $8, BB calls
Turn: 8♣, Pot $29, BB checks, Button bets $20, BB calls
River: 3♠, Pot $69, BB checks, Button bets $50 (3/4 pot)
Hero Hand: Q♠9♠

Thought Process:

1. “Who has a structural advantage on this board?”
   → The Button has a range advantage; a large river bet suggests a polarized range.
2. “What role does my hand play within my range?”
   → Q9 is top pair with a weak kicker, a bluff-catcher candidate, but 9♠ blocks the opponent's possible bluffs (J9, 98).
3. “Does my opponent have enough hands to fold / do they call often?”
   → If the opponent's bluffing range contains many 9x hands, my holding 9♠ reduces their bluffing probability. The call EV might be low.

Conclusion: Fold

Comment: Since 9♠ blocks the opponent's possible bluffs, their probability of bluffing decreases. The call EV may be lower than with a bluff-catcher without a blocker (e.g., QJ).

Example 3: Using Blockers for a Turn Semi-Bluff

Game: Cash game 1/2, Stack 200BB
Position: Cutoff
Preflop: CO raises $6, Button calls
Flop: K♦9♦4♠, Pot $15, CO bets $10, Button calls
Turn: 6♦, Pot $35
Hero Hand: A♦Q♦

Thought Process:

1. “Who has a structural advantage on this board?”
   → CO raised and has an advantage on a K-high board. A flush completed on the turn.
2. “What role does my hand play within my range?”
   → A♦Q♦ is a nut flush draw, and holding A♦ blocks the opponent's flush.
3. “Does my opponent have enough hands to fold / do they call often?”
   → The opponent is likely to hold Kx, and the A♦ blocker reduces the opponent's flush probability. A bet can induce a fold.

Conclusion: Turn bet $25 (3/4 pot)

Comment: Holding A♦ lowers the opponent's probability of holding the nut flush. Even if the draw misses, a river bluff opportunity may arise.

Example 4: Using Blockers for 3-bet Bluff Construction

Game: Cash game 1/2, Stack 200BB
Position: Big Blind
Preflop: Cutoff raises $6
Hero Hand: A♠5♠

Thought Process:

1. “Who has a structural advantage on this board?”
   → Preflop 3-bet spot, A♠5♠ is a weak hand, but holding an A blocks the opponent's AK, AQ.
2. “What role does my hand play within my range?”
   → A♠5♠ is a 3-bet bluff candidate; the A blocker limits the opponent's 4-bet call/5-bet range.
3. “Does my opponent have enough hands to fold / do they call often?”
   → The opponent's probability of holding AK, AQ decreases, reducing their 4-bet frequency. The 3-bet bluff's success rate increases.

Conclusion: 3-bet $20 (3.3x)

Comment: Holding an A reduces the opponent's premium hand combinations. Including hands like A5s in your 3-bet bluff range helps maintain balance.

Key Pattern Summary

Pattern 1: Blocker = The cards you hold limit your opponent's specific hand combinations.

Pattern 2: When bluffing, holding key cards of the nut hand (A, K) increases bluff frequency.

Pattern 3: For bluff-catchers, holding cards that block your opponent's bluffs decreases call frequency.

Pattern 4: Bluffing on a flush board with A♠ → Opponent's nut flush probability ↓

Pattern 5: Using Ax suited, KQs for 3-bet bluffs → Blocks opponent's AK, AQ, KQ

Pattern 6: Using nut draw blockers for turn semi-bluffs → Opponent's strong made hand probability ↓

Pattern 7: Reverse Blocker = You don't hold a specific card, increasing your opponent's probability of holding that hand ↑

Pattern 8: Blockers are auxiliary tools; range and board texture take precedence.

Quiz

Question 1

What is the core concept of a blocker?

• A) Holding a strong hand to pressure your opponent
• B) The cards you hold physically limit your opponent's specific hand combinations
• C) A strategy to reduce your opponent's bet size
• D) A method for calculating pot odds

Question 2

A flush board completed on the river, and Hero holds A♠6♥ (air). What is the advantage when considering a bluff?

• A) A♠ blocks the opponent's nut flush, increasing the bluff's success rate.
• B) A♠ is a high card, so the probability of winning at showdown is high.
• C) 6♥ blocks the opponent's pair.
• D) No advantage.

Question 3

In a bluff-catcher situation, Hero holds Q♠9♠ (top pair weak kicker), and the opponent made a large bet on the river. If 9♠ blocks the opponent's possible bluffs (J9, 98), what is the best way to respond?

• A) Increase call frequency
• B) Decrease call frequency (consider folding)
• C) Raise
• D) Ignore blockers and only consider hand strength

Question 4

Why is A5s a good bluff candidate when constructing a 3-bet bluff?

• A) Because A5s is a strong hand
• B) Because holding an A blocks the opponent's AK, AQ, reducing their 4-bet frequency
• C) Because 5 is a low card
• D) Because it's suited and can make a flush

Question 5

What is the most important thing to be careful about when using blockers?

• A) Making decisions based solely on blockers can lead to mistakes. Range and board texture take precedence.
• B) Blockers are always accurate, so you can decide based solely on them.
• C) Blockers are only important preflop.
• D) Blockers are only important on the river.

Answers and Explanations

Question 1

Answer: B) The cards you hold physically limit your opponent's specific hand combinations

Explanation: A blocker is the concept that because you hold a specific card, your opponent cannot make a hand including that card. For example, if you hold A♠, your opponent cannot have the nut flush including A♠.

Question 2

Answer: A) A♠ blocks the opponent's nut flush, increasing the bluff's success rate.

Explanation: If you hold A♠, your opponent's probability of having the nut flush (including A♠) decreases. This reduces the likelihood of your opponent holding a strong hand, which can increase your bluff success rate.

Question 3

Answer: B) Decrease call frequency (consider folding)

Explanation: If 9♠ blocks the opponent's possible bluffs (J9, 98), their probability of bluffing decreases. This means the opponent's range is weighted towards value, so the call EV might be low. It may be better to consider folding.

Question 4

Answer: B) Because holding an A blocks the opponent's AK, AQ, reducing their 4-bet frequency

Explanation: A5s blocks the opponent's premium hands (AK, AQ) because it holds an A. The opponent's probability of 4-betting decreases, and their likelihood of folding to a 3-bet increases, making it a good bluff candidate.

Question 5

Answer: A) Making decisions based solely on blockers can lead to mistakes. Range and board texture take precedence.

Explanation: Blockers are useful tools but play a supplementary role. More important factors such as range advantage, board texture, and position should be considered first, and blockers are best utilized in marginal decisions.