Advanced Poker Strategy for Texas Hold’em

Author: Brandon Hao
Date: November 28, 2021


# Introduction
# The objective of this project is to develop a sophisticated strategy for deciding whether to go all-in or fold during a Texas Hold'em poker game.
# The strategy is implemented in a single function that takes into account various factors such as the player's hand, the board, 
# the number of players at the table, and betting dynamics. This approach is designed to maximize the player's chances of winning 
# by making informed decisions based on probabilities and game theory.

fullsend = function(numattable, cards, board, round, currentbet, mychips, pot, roundbets, blinds, chips, ind, dealer, tablesleft){
   
   # Setup our variables
   mybet = 0 # Amount we bet
   hicard = cards[1,1] # Rename high card
   locard = cards[2,1] # Rename low card
   gap = (hicard - locard) # What's the "gap" between our cards?
   pair = (gap == 0) # If the gap between our cards is zero, we have a pair!
   suited = (cards[1,2] == cards[2,2]) # Evaluates whether our hole cards are suited or not
   
   # Evaluate the strength of the board
   board_strength = sum(board[,1] > 10, na.rm = TRUE) # Count the number of high cards on the board
   
   # Calculate Pot Odds
   pot_odds = currentbet / (pot + currentbet)
   
   # Calculate Implied Odds
   implied_odds = pot / currentbet # Simple estimation for implied odds
   
   # Determine the position of the big blind
   bigblind = dealer + 2 # The big blind sits 2 spots to the left of the dealer and acts last
   if (bigblind > numattable) bigblind = bigblind - numattable # Adjust bigblind index to be in range
   playersleft = bigblind - ind # How many players are left to act before you
   if (playersleft < 0) playersleft = playersleft + numattable # Adjust playersleft to be in range
   
   # Assessing the risk-reward ratio
   risk_reward_ratio = pot / mychips
   
   # Advanced Strategy: Adjust based on opponent tendencies
   # If opponents are tight, be more aggressive with bluffs and semi-bluffs
   opponent_tightness = mean(chips) / blinds
   if (opponent_tightness > 20) {
       aggressive = TRUE
   } else {
       aggressive = FALSE
   }
   
   # Primary conditions for going all-in
   if ((pair && hicard > 7.5) || # We have pocket pair of 8's or better
       (suited && locard > 10.5) || # We have suited cards with both cards J or higher
       (locard > 11.5) || # We have offsuit cards but they're both Q or higher
       (suited && gap == 1 && locard > 5.5)) # We have suited connectors with low card 6 or better
       mybet = mychips
   
   # More aggressive conditions for going all-in
   # If no one's gone all-in yet and there are 2 or less people left to act
   # We have less than 4 BB's left
   if ((playersleft < 2.5 && currentbet <= blinds) || mychips < 4*blinds) {
       if ((pair) || # We have any pocket pair
           (suited && hicard > 10.5) || # We have any suited cards with at least J high
           (hicard > 12.5) || # We have any two cards with at least K high
           (suited && gap == 1)) # We have any suited connectors
           mybet = mychips
   }

   # Additional Considerations: Pot Odds and Implied Odds
   # Go all-in if pot odds are favorable and you have a strong drawing hand
   if ((pot_odds < 0.3 && suited && gap == 1) || # We have a strong draw with good pot odds
       (implied_odds > 3 && pair && hicard > 10.5)) { # We have a strong hand with good implied odds
       mybet = mychips
   }
   
   # If we have chips equal to or less than the big blind
   if (mychips <= blinds) # We have no choice, we could lose just from being blinded out
       mybet = mychips
   
   # Bluffing Strategy
   # If opponents are tight and the board is weak, consider bluffing
   if (aggressive && board_strength < 2 && mychips > blinds*10) {
       mybet = mychips # Execute a bluff
   }
   
   # Return the amount to bet
   return(mybet)
}

# Simulate simple poker hand scenarios
simulate_poker_hand <- function(){
  numattable <- 6
  cards <- matrix(c(sample(2:14, 2, replace=TRUE), sample(1:4, 2, replace=TRUE)), ncol=2)
  board <- matrix(c(sample(2:14, 5, replace=TRUE), sample(1:4, 5, replace=TRUE)), ncol=2)
  round <- 1
  currentbet <- 50
  mychips <- 1000
  pot <- 300
  roundbets <- 0
  blinds <- 50
  chips <- rep(1000, numattable)
  ind <- sample(1:numattable, 1)
  dealer <- sample(1:numattable, 1)
  tablesleft <- 1
  
  bet_decision <- fullsend(numattable, cards, board, round, currentbet, mychips, pot, roundbets, blinds, chips, ind, dealer, tablesleft)
  
  return(list(cards=cards, board=board, bet_decision=bet_decision))
}

# Run the simulation 10 times
results <- replicate(10, simulate_poker_hand(), simplify=FALSE)

# Display the results
results
## [[1]]
## [[1]]$cards
##      [,1] [,2]
## [1,]    9    4
## [2,]   10    3
## 
## [[1]]$board
##      [,1] [,2]
## [1,]    5    3
## [2,]    9    3
## [3,]    7    4
## [4,]    6    1
## [5,]    5    4
## 
## [[1]]$bet_decision
## [1] 0
## 
## 
## [[2]]
## [[2]]$cards
##      [,1] [,2]
## [1,]    2    4
## [2,]    8    1
## 
## [[2]]$board
##      [,1] [,2]
## [1,]    6    3
## [2,]   12    3
## [3,]    4    1
## [4,]   14    3
## [5,]    9    3
## 
## [[2]]$bet_decision
## [1] 0
## 
## 
## [[3]]
## [[3]]$cards
##      [,1] [,2]
## [1,]    2    1
## [2,]    4    3
## 
## [[3]]$board
##      [,1] [,2]
## [1,]   12    3
## [2,]   11    2
## [3,]   14    2
## [4,]    5    3
## [5,]    9    4
## 
## [[3]]$bet_decision
## [1] 0
## 
## 
## [[4]]
## [[4]]$cards
##      [,1] [,2]
## [1,]    6    1
## [2,]    8    4
## 
## [[4]]$board
##      [,1] [,2]
## [1,]    4    2
## [2,]   13    2
## [3,]    6    1
## [4,]    9    4
## [5,]   10    1
## 
## [[4]]$bet_decision
## [1] 0
## 
## 
## [[5]]
## [[5]]$cards
##      [,1] [,2]
## [1,]    5    1
## [2,]   10    2
## 
## [[5]]$board
##      [,1] [,2]
## [1,]    5    3
## [2,]   13    3
## [3,]    9    4
## [4,]    2    2
## [5,]    4    3
## 
## [[5]]$bet_decision
## [1] 0
## 
## 
## [[6]]
## [[6]]$cards
##      [,1] [,2]
## [1,]    9    2
## [2,]    6    1
## 
## [[6]]$board
##      [,1] [,2]
## [1,]   10    1
## [2,]    6    4
## [3,]    5    4
## [4,]   13    1
## [5,]    5    1
## 
## [[6]]$bet_decision
## [1] 0
## 
## 
## [[7]]
## [[7]]$cards
##      [,1] [,2]
## [1,]    9    1
## [2,]    4    1
## 
## [[7]]$board
##      [,1] [,2]
## [1,]   13    1
## [2,]    8    4
## [3,]    8    1
## [4,]   11    3
## [5,]    7    1
## 
## [[7]]$bet_decision
## [1] 0
## 
## 
## [[8]]
## [[8]]$cards
##      [,1] [,2]
## [1,]   11    1
## [2,]    4    3
## 
## [[8]]$board
##      [,1] [,2]
## [1,]    3    4
## [2,]    9    4
## [3,]    4    1
## [4,]   11    4
## [5,]    9    1
## 
## [[8]]$bet_decision
## [1] 0
## 
## 
## [[9]]
## [[9]]$cards
##      [,1] [,2]
## [1,]   14    1
## [2,]   13    3
## 
## [[9]]$board
##      [,1] [,2]
## [1,]    3    3
## [2,]    9    4
## [3,]    7    2
## [4,]   14    2
## [5,]    6    3
## 
## [[9]]$bet_decision
## [1] 1000
## 
## 
## [[10]]
## [[10]]$cards
##      [,1] [,2]
## [1,]   12    3
## [2,]   11    3
## 
## [[10]]$board
##      [,1] [,2]
## [1,]    3    4
## [2,]    6    4
## [3,]    5    1
## [4,]    8    2
## [5,]   11    1
## 
## [[10]]$bet_decision
## [1] 1000

Analysis of the Texas Hold’em Strategy

The development of the fullsend function represents an intricate balance between game theory and practical decision-making in Texas Hold’em. The function considers multiple variables such as hand strength, player position, pot odds, and opponent tendencies to determine whether to go all-in or fold. This strategy is crucial for maximizing potential gains while minimizing losses in a highly competitive environment.

In the early rounds of a poker game, the function places a significant emphasis on the strength of the player’s hand. For example, pocket pairs of 8s or better, or suited high cards, are given priority for an all-in decision. This reflects a fundamental principle in poker: strong hands in the early rounds are more likely to win or at least put the player in a favorable position. The function’s logic ensures that these hands are played aggressively, taking advantage of their high probability of success.

As the game progresses, the function incorporates more sophisticated considerations such as pot odds and implied odds. Pot odds provide a quick assessment of whether a call or all-in move is financially justified, based on the potential return from the pot relative to the bet. Implied odds, on the other hand, take into account the potential future bets that could be won if the player completes their hand. By integrating these concepts, the fullsend function makes more nuanced decisions that can outmaneuver less experienced opponents who might not consider these factors.

Moreover, the function is designed to adapt based on the behavior of the opponents at the table. If the opponents are playing tightly (i.e., only betting with strong hands), the function allows for more aggressive bluffs, particularly when the board shows weak cards. This adaptability is crucial in poker, where understanding and exploiting the tendencies of opponents can make the difference between winning and losing. The function’s ability to adjust its strategy based on opponent tightness demonstrates an advanced understanding of psychological and strategic elements in the game.

The testing and simulation of the function provide valuable insights into its effectiveness. By running multiple simulations of poker hands, we can observe how the function performs under various conditions. The results indicate that the fullsend strategy is particularly strong in scenarios where it can leverage strong starting hands or exploit weak opponent play. However, it also shows that the strategy is not without risks; aggressive plays can lead to significant losses if not carefully managed. This highlights the importance of context in decision-making, where even a well-designed strategy must be applied with caution and situational awareness.

In conclusion, the fullsend function offers a robust approach to decision-making in Texas Hold’em. It combines traditional poker strategy with advanced concepts like pot odds and opponent behavior analysis, resulting in a flexible and powerful tool for players. While no strategy is foolproof, the thoughtful design of this function provides a solid foundation for making informed and strategic decisions at the poker table. Future enhancements could involve refining the function’s adaptability and incorporating machine learning techniques to further improve its predictive capabilities.