Class Notes for Probability & Statistics I (Math 3350)

Total Page:16

File Type:pdf, Size:1020Kb

Class Notes for Probability & Statistics I (Math 3350) Class Notes for Probability & Statistics I (Math 3350) R. Sinn North Georgia College & State University August 25, 2009 Abstract A poker-based introduction to probability and statistics. Almost all the examples are real poker problems from No Limit Texas Holdem (NLHE) whose answers interest winning players. 1 Basic Probability 1.1 Organizing Principals Professional gamblers and poker players actually use mathematics to earn a living. Career paths for professional gamblers include running casinos and betting parlors in places where such things are legal. They o¤er odds for betting on athletic events and various races. They design and perfect games of chance for the casino ‡oor and verify that the games are fair. Well, some do. Professional poker players are currently the most high pro…le examples of professional gamblers. Ten years ago, few people outside Vegas knew of the legendary Doyle Brunson. Today, many of us can name poker celebrities like Phil Ivey, the "Poker Brat" Phil Hellmuth or Annie Duke having seen them playing high stakes poker on TV. What matematics do they use? They use probability theory to predict the future. They use statistics to analyzes the past. With an understanding of both, they manufacture hundreds of "small edges" over their competition to earn money. 1 A roulette ball falling into its slot and a card drawn from a well-shu• ed deck are two example of probability experiments. A probability experi- ment is any event whose outcomes are perfectly random and exactly pre- dicted by probabilities. The probability space (or sample space) is the col- lection of all possible outcomes of the experiment. A simple random sample (SRS) is a collection of outcomes drawn at random from the probability space S. An event is set of outcomes. We use set notation: an event A is a subset of S. Determining probabilities typically devolves into a counting excercise. We simply count the number of outcomes in event A and divide by the number of outcomes in S. To simplify our work, we will use the cardinality operator n(A) to indicate "the number of elements (outcomes) in set (event) A." This leads us to the only formula in discrete probability theory: n(A) P (A) = n(S) Example 1 Suppose we draw a single card at random from a well-shu• ed standard deck of 52 cards. What is the probability of drawing a heat? Let the event (set) H represent the 13 "hearts" outcomes. Then n(H) 13 1 P (A) = n(S) = 52 = 4 Generally, in probability caclulations, the compound event "A or B" means A B, while "A and B" indicates A B. Independence of the events causes[ a vital divergence. Sets A and B\ are independent provided A B = ?. \ 1. For indepedent sets: P (A B) = P (A) + P (B). [ 2. For dependent sets: P (A B) = P (A) + P (B) P (A B). [ \ 2 Note that when A B = ?, then by de…nition P (A B) = 0 since \ \ n(?) = 0. The cardinality of set with no elements is zero. We could about the probability of drawing one card and getting both an Ace and an 8. The events are certainly independent. But they can never occur simultaneously. For dependent sets, we typically have to …nd a creative way to count n(A B). Strategically, our counting job is much easier if we can partition the event\ into independent sets. When this is not possible, the formula is based on an idea called the "principal of inclusion-exclusion." The basic problem is that, when we sum, the outcomes in the "overlap" or intersection are counted twice. So we exclude them by subtracting. For three depedenet sets A, B and C, we have: P (A B C) = P (A) + P (B) + P (C) P (A B) [ P ([A C) P (B C) + P (A B C) \ \ \ \ \ We count all the two-way overlaps twice, and throw them out. In the process we "exclude" the three-way overlap three times - it was added three times - so now it has be included again. The same idea works regardless of how many sets are involved, but the results are tedious and in the long tradition of math texts are therefore left to the reader. It is often far easier to count the outcomes in the complement of event A, e.g. the probability that event A does not occur. We denote set com- plement as Ac. The formula is: c P (Ac) = n(A ) = 1 P (A) n(S) In probability calculations, we often …nd the notion of "throwing away" the overlap between two sets useful. This helps us identify independent sets. Given two events A and B such that A B = ?, the event "A but not B" is given by A Bc which we denote as A\ B6. \ n Example 2 Hero holds A J , and ‡op comes J 9 3 . Hero feels he will win with any club| (‡ush),| Jack (set), or Ace~ (two| pair),| but feels otherwise his hand is worse than his opponents. He believes he will lose unless his hand improves. What is his probability of making a winning hand on the next card? 3 Let A represent the event of a turning an Ace, and let C represent the event of turning a club. Since Hero holds the A , A C = ?, and thus P (A C) = P (A) + P (C). Hero can see four clubs,| the\ two in his hand and the two[ on the board. So n(C) = 9. There are three Aces left, so n(A) = 3. We know where …ve the 52 cards in the deck are, so: P (A C) = n(A)+n(C) = 3+9 = 12 [ n(S) 47 47 Example 3 Hero holds J T , and ‡op comes K Q 3 . Hero feels he will win with a straight, but~ worries} that Villain holds~ two| clubs| (‡ushes beat straights). What is his probability of making the winning hand on the next card? Let T be the event Hero turns a straight card (any A or 9), and let F be the event a ‡ush card hits (any club). Here, the winning event for Hero is T F , and n(T F ) = 8 2, that is the 8 straight cards from which we "thrown away" the An and the 9 . The solution is 6 . | | 47 Example 4 Hero faces one villain heading to the ‡op where Hero bets last. It is known that the probability of "hitting the ‡op" with any two unpaird cards is approximately 1/3. Hero decides to blu¤ his opponent. What is the probability his opponent "missed" the ‡op and will therefore be likely to fold? Let H be the event of "hitting the ‡op," e.g. pairing one (or more) of the board cards. The important probability is knowing that P (not H) = 1 2 1 3 = 3 . Aggressive poker players use this likelihood of "unimproved" cards in villain’shand to bet (blu¤) on the ‡op. This is so common it has a name: a continuation bet, or cbet. 4 1.1.1 Odds One of the more confusing aspects of Vegas-style betting is that gamblers tend to state probabilities in terms of odds rather than percentages. A weatherman would say "there’s a 70% chance of rain tomorrow." A gam- ber would lay 7 to 3 odds for rain tomorrow. A percentage probability is 7 based on the fraction, here, 10 . In fractional probabilities, we give the "num- ber of successes" divided by the "total outcomes." For odds, we give a ratio of "number of successes" to "number of failures." The order is important: success to failure. Poker players know a host of odds. For example, Hero faces odds of roughly 7.5 to 1 against ‡opping set when starting with a poket pair (pp). The "against" turns the odds around, meaning there is likely to be "1" success for each "7.5" failures. To convert to a probability, we …nd the denominator by …rst adding successes and failures. Let FS be the event of ‡opping a set given that Hero starts with a pp. Then: 1 1 2 P (FS) = 7:5+1 = 8:5 = 17 = 0:117 65 Suppose Hero holds TT while his opponent holds 55. Hero is about a 4 to 1 favorite. This means that a hand like TT will beat a hand like 55 about 4 times in 5, or 80% of the time. Poker players tend to use both percentage chance of winning (called eq- uity) and odds, depending upon the situation. When betting, knowing one’s odds is more useful since it allows us to match our bet-to-pot ratio and com- pare it to our successes-to-failure ratio. For example, Hero estimates his chances of winning the pot are 1 in 3, or 2 to 1 against. Villain bets $50 into a $100 pot. Hero must call $50 for a chance to win $150. Hero has 2 to 1 odds (against) making his hand, but the pot is "laying him" 3 to 1 odds ($150 to $50). In this case, it is best for Hero to call, since the odds against him making his hand are lower than the pot odds. 1.1.2 Equity Once you understand the ratio vs. fraction concept, converting odds to probabilities is pretty simple and can usually be at least estimated in your 5 head. Going from percentages to odds can be a bit more tricky. Poker players tend to use various odds calculators like PokerStove (highly recommended, free – google "Poker Stove").
Recommended publications
  • Site Review: Innovation
    Site Review: Website: www.americascardroom.eu Americas Cardroom has brought the excitement of online poker back to the USA! Americas Cardroom has grown rapidly over the past several years, bringing players back to the glory days of online poker in the US through unique incentives and promotions. They are the only US facing site to offer The Million Dollar Sunday $1,000,000 GTD poker tournaments while hosting a weekly progressive rake race for both cash game and Sit & Go players. Americas Cardroom is truly living up to its name as being the online poker site that US players can trust. As the flagship skin of the Winning Poker Network, Americas Cardroom has already grown into one of the top communities for US poker players thanks to its no-nonsense deposits, quick payouts and high tournament guarantees. Reasons to join America’s Cardroom - Rated fastest Payouts in the industry - US players Accepted - WSOP Qualifiers - Million Dollar Sundays $1,000,000 GTD Tournaments - The only site with weekly progressive rake races for sit & go’s and cash games - Now accepts Bitcoin for Deposits and Withdrawals Poker Network: THE WINNING POKER NETWORK (WPN) Innovation $1,000,000 GTD Million Dollar Sundays -Americas Cardroom brought back the glory days of poker to the US market in 2015 with $1,000,000 GTD Million Dollar Sunday tournaments. More are on tap for 2016 with the next one scheduled for April 24th at 4pm ET. They are the only US facing network to offer tournaments close to this magnitude. Tournament Series-Americas Cardroom runs numerous online poker tournament series throughout each year.
    [Show full text]
  • How to Play I Luv Suits Poker Your Guide to Playing Casino Table Games Playing the Game
    HOW TO PLAY I LUV SUITS POKER YOUR GUIDE TO PLAYING CASINO TABLE GAMES PLAYING THE GAME The Object of I Luv Suits Poker™ is to get a flush with more cards than the dealer. I Luv Suits Poker also offers the optional Flush Rush and Super Flush Rush Bonus wagers. Getting Started You make the ante wager to begin play. You may also make the Flush Rush and Super Flush Rush Bonus wagers. The dealer will give a packet of 7 cards to each participating player and to themselves. After seeing your cards, you will have the option to either fold or make the play wager based on the amount of cards in your flush: • If your hand contains a three or four-card flush, you may only bet 1x your ante. • If your hand contains a five-card flush, you may bet 1x or 2x your ante. • If your hand contains a six-card flush or higher, you may bet 1x, 2x or 3x your ante. Winning and Losing Once all player decisions have been made the dealer will reveal their cards. The dealer’s hand must contain a three-card 9-high flush or better to qualify. If the dealer’s hand does not qualify, your play bet will be returned and your ante bet will be paid 1-to-1. If your hand wins, the ante and play bets pay 1 to 1. If the dealer beats your hand, the ante and play bets lose. If the dealer ties your hand, the ante and play bets both push.
    [Show full text]
  • TOP 5 POKER - Rules & Dealing Procedures
    TOP 5 POKER - Rules & Dealing Procedures 1. The layout used for "Top 5 Poker" has either 6 or 7 spots and fits on a standard blackjack size table. Each spot has a "Wager Area" that consists of 4 wager locations: 1) "Ace or Face Community Card", 2) "10's or Better", 3) "Ante" and 4) "Bet". Payouts are posted on the layout between the spots. 2. Top 5 Poker is played using only 1 standard deck of 52 cards. 3. After the cards are shuffled, the dealer first checks to ensure that all players that wish to play the next round have all of their wagers placed. Players make an "Ace or Face Community Card" and/or a "10's or Better" and/or an "Ante" wager in their Wager Area to show they are playing the next round. The house determines which initial wager or wagers are required. 4. The dealer deals 5 cards to each player’s spot that has a wager in the 10's or Better and/or Ante wager locations. Each set of 5 cards is dealt face down, to the player's side of the Wager Area, the dealer may deal with one arm motion to facilitate dealing from a shuffling machine. The dealer then deals 5 cards, face down, to himself. Once dealing of the round starts, players that have not placed a wager in their Wager Area are not allowed to play the round. Note: The house will define what constitutes a mis-deal and determine the procedures to handle any such mis-deal.
    [Show full text]
  • Mike's Cardroom
    Pai Gow Poker with Wrangler Push and Outlaw 9 High or Better Bonus Bet Type of Game The game of Pai Gow Poker with Wrangler Push and Outlaw 9 High or Better Bonus Bet utilizes a player-dealer position and is a California game. The player-dealer shall collect all losing wagers, pay all winning wagrs, and may not win or lose more than the original amount wagered. Once the player-dealer’s wager has been exhausted, the wagers not covered by the player-dealer shall be returned to the respective players. The player-dealer may only ‘bank” the hand (including bonus bets) for two consecutive rounds of play before it is offered in a clockwise fashion around the gaming table. The gambling enterprise does not participate in the actual play of the game and has no interest in the outcome of the play. Object and Summary of the Game This game uses the traditional Pai Gow Poker game and adds two bonus bets, Wrangler Push Bonus Bet and Outlaw 9 High or Better Bonus Bet. The bonus bets have to be placed prior to the hands being played. A player has the option to place a Wrangler Push wager and the wager will win when the player’s hand and the player-dealer’s hand push. This Wrangler Push Bet pays 1:1 except when there is a pair of 3’s or higher, then it will pay 2:1. In addition, a player has the option to place an Outlaw 9 High or Better Bonus Bet wager and the wager will win when the wagered hand of seven cards consists of an Ace high or lower.
    [Show full text]
  • View Gaming Guide
    poker philadelphia.livecasinohotel.com 900 Packer Avenue, Philadelphia, PA 19148 GAMBLING PROBLEM? Call 1-800-GAMBLER 10. In most situations, a player who has no interest POKER GUIDE in the pot should still hold onto their hand although no-one has bet. They should not fold, even in turn, TABLE OF CONTENTS because another player may gain an advantage over 1. Poker Etiquette .......................Pg. 1-2 a competitor by that act. 2. House Policies......................... Pg. 3 11. Arranging one’s chips to conceal higher 3. Buy In . Pg. 3 denominations is not allowed. 4. Table Stake / All In . Pg. 3 12. “Splashing the pot,” throwing chips into the pot 5. Operating Procedure & Policy ........... Pg. 3 so they become mingled with chips that are already 6. Texas Hold ‘Em . .Pg. 4-5 there, making the amount wagered unverifiable, is 7. Omaha Poker........................ Pg. 5-6 inappropriate. 8. Seven Card Stud......................Pg. 7-8 9. Badugi Poker.........................Pg. 8-9 13. If a player expects to be leaving the game for a long 10. 2-7 (Deuce to Seven) ................... Pg. 9 time, a supervisor should be notified. 11. Poker Hand Rankings ..................Pg. 10 14. A player is entitled to quit the game any time they 12. Glossary of Poker Terminology ........Pg. 11-14 choose, without suffering criticism. 13. Proper Conduct........................Pg. 14 15. Criticism of the way another player has elected to play their hand, or their general style of play, is POKER ETIQUETTE: impolite and undesirable. 1. Language, dress, hygiene and behavior should be of 16. Lengthy post-mortems about a hand are unwelcome.
    [Show full text]
  • The Game of Texas Hold'em 3
    The Intelligent Guide to Texas Hold'em Poker Copyright O 2003 by Intelligent Games Publishing Book cover writing by Susan Kendrick Writing All rights reserved. No part of this book may be used or reproduced in any manner, or distributed through any medium, including photocopying, electronic data stor- age and transmission via the Internet, without written consent from the publisher. Exceptions are usage of brief quotations for the purposes of criticism and review. For information contact: Intelligent Games Publishing P. 0.Box 6705, Towson, MD 21285 Web Site: www.intelligentpoker.com E-mail: [email protected] Write the publisher for bulk price quotes. ISBN 0-9677551-2-3 Library of Congress Control Number: 2003100272 Publisher's Cataloging-in-Publication (Provided by Quality Books, Znc.) Braids, Sam. The intelligent guide to Texas hold'em poker / Sam Braids. p. cm. Includes bibliographical references and index. LCCN 2003 100272 ISBN 0967755 123 1. Poker. 2. Gambling. I. Title. GV 125 1.B73 2003 795.41'2 QBI03-20008 I PLEASE NOTE: The material contained in this book is for informational pur- poses only. In no manner should this book be construed to offer legal advice on the issue of online gambling. It is the reader's responsibility to know and follow the laws that apply in his or her state and jurisdiction. Seek appropriate legal advice from a qualified attorney if unsure. The publisher does not endorse or guarantee any of the services described in this book. The reader assumes all risks and respon- sibility for his or her actions. If you do not agree with these conditions, you may return this book to the publisher for a full refund.
    [Show full text]
  • History of Texas Holdem Poker
    GAMBLING History of Texas Holdem Poker ever in the history of poker has it been as popular as nowadays. The most played poker game is definitely exasT Hold em. All Nover the world people are playing Texas Hold em games and there seems to be no end to the popularity of the game. Espe- cially playing Texas Hold em for free on the Internet has became extremely popular in the last years. Who actually invented this great poker game? This was a game, played in the 15th century, that was played with the card deck as we know it Where did it originally come from? And how today. It was a card game that included bluffing and betting. did free Texas Hold em games end up on the internet? To answer these questions it is The French colonials brought this game to Canada and then to the United States in the early important to trace back the history of poker, to 17th century, but the game didn’t became a hit until the beginning of the 18th century in New find out where it all began. Orleans. HISTORY OF POKER THEORIES During the American Civil War, soldiers played the game Pogue often to pass the time, all over the country. Different versions evolved from this firstPogue game and they were called ‘‘Stud’’ There are many different theories about how and ‘‘Draw’’. The official name for the game turned into ‘‘Poker’’ in 1834 by a gambler named poker came into this world and there seems to Jonathan H. Green. be no real proof of a forerunner of the game.
    [Show full text]
  • Ultimate Texas Hold ‘Em
    ULTIMATE TEXAS HOLD ‘EM 1. Definitions The following words and terms, when used in the Rules of the Game of Ultimate Texas Hold ‘Em, shall have the following meanings unless the context clearly indicates otherwise: Ante-- or “ante wager” means an initial wager, separate from but equal in amount to the player’s blind wager, required to be made prior to any cards being dealt in order to participate in the round of play. Blind-- or “blind wager” means an initial wager, separate from but equal in amount to the player’s ante, required to be made prior to any cards being dealt in order to participate in the round of play. Burn-- means to remove the top or next card from the deck and place it face down in the discard rack without revealing it to anyone. Check-- means that the player waives the right to place a play wager but remains in the round of play. Community card-- means any of the five cards dealt face up in the center of the table, all of which may be used by each player and the dealer together with his or her own two cards to form the best possible five-card poker hand. Flop-- means the first three community cards dealt face up in the area designated for the placement of the community cards. Fold-- means the withdrawal of a player from a round of play by discarding his or her two cards and not making a play wager. Hand-- or “poker hand” means the highest ranking five-card hand that can be formed from the five community cards and the two cards dealt to the dealer or a player.
    [Show full text]
  • The Mathematics of Poker: Basic Equity Calculations
    - MATHEMATICS AND COMPUTER EDUCATION- THE MATHEMATICS OF POKER: BASIC EQUITY CALCULATIONS AND ESTIMATES Mark Farag Gildart Haase School of Computer Sciences and Engineering Fairleigh Dickinson University 1000 River Road, Mail Stop T-BE2-01 Teaneck, New Jersey 07666 [email protected] INTRODUCTION The game of poker has experienced a worldwide boom in popularity in the past decade. This can be attributed to a confiuence of events: the invention of the "lipstick" camera that allows viewing of players' "hole" (hidden) cards for television broadcasts, the growth of online poker rooms, and the increased popularity of "satellite" events that allow players to win their way into larger-money events. The largest single prize awarded in a poker tournament to date, 12 million US dollars, was won by an amateur player in 2006 [2]. Poker is a game of skill that contains an element of chance; it lies somewhere between chess (pure skill) and roulette (pure luck) in the spectrum of games. Since poker is a game of incomplete information, skilled players often use psychology to help them make correct decisions or to infiuence others to make incorrect decisions. Some situations do arise, however, in which mathematical considerations are paramount. It is the purpose of this article to discuss such situations. Since the first section covers the rules of poker in detail, the subsequent discussion should be of interest and accessible to students with only a basic knowledge of combinatorics and probability. THE RULES Modem poker is played with a standard deck of 52 cards, using cards marked with numbers 2 through 10, J (Jack), Q (Queen), K (King), and A (Ace) to indicate, in increasing order, their respective ranks.
    [Show full text]
  • Six Card Bonus for Five Poker Derivatives
    Full text of the proposal follows (additions indicated in boldface thus; deletions indicated in brackets [thus]): 13:69E-1.13H Let it ride poker table; physical characteristics (a) (No change.) (b) The layout for a let it ride poker table shall contain, at a minimum: 1. – 4. (No change.) 5. The payout odds for all authorized wagers, including the let it ride bonus wager authorized by N.J.A.C. 13:69F-18.6A, [and] the three-card bonus wager authorized by N.J.A.C. 13:69F-18.6B, the six-card bonus wager authorized by N.J.A.C. 13:69-18.6C, if the casino licensee offers [either] any of the optional [wager] wagers; 6. (No change.) 7. If a casino licensee offers the optional three-card bonus wager authorized by N.J.A.C. 13:69F-18.6B, a separate designated area at each betting position for the placement of the three-card bonus wager; and 8. If a casino licensee offers the optional six-card bonus wager authorized by N.J.A.C. 13:69F-18.C: i. A separate designated area at each betting position for the placement of the six-card bonus wager; and ii. A separate designated area for the placement of the six-card bonus wager community cards. (c) – (e) (No change.) 2 13:69E-1.13P Four-card poker table; physical characteristics (a) - (b) (No change.) (c) If a casino licensee offers the variation of four card poker authorized by N.J.A.C. 19:47-27.10A, the layout for the table shall, at a minimum, contain: 1.
    [Show full text]
  • Early Round Bluffing in Poker Author(S): California Jack Cassidy Source: the American Mathematical Monthly, Vol
    Early Round Bluffing in Poker Author(s): California Jack Cassidy Source: The American Mathematical Monthly, Vol. 122, No. 8 (October 2015), pp. 726-744 Published by: Mathematical Association of America Stable URL: http://www.jstor.org/stable/10.4169/amer.math.monthly.122.8.726 Accessed: 23-12-2015 19:20 UTC Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at http://www.jstor.org/page/ info/about/policies/terms.jsp JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Mathematical Association of America is collaborating with JSTOR to digitize, preserve and extend access to The American Mathematical Monthly. http://www.jstor.org This content downloaded from 128.32.135.128 on Wed, 23 Dec 2015 19:20:53 UTC All use subject to JSTOR Terms and Conditions Early Round Bluffing in Poker California Jack Cassidy Abstract. Using a simplified form of the Von Neumann and Morgenstern poker calculations, the author explores the effect of hand volatility on bluffing strategy, and shows that one should never bluff in the first round of Texas Hold’Em. 1. INTRODUCTION. The phrase “the mathematics of bluffing” often brings a puzzled response from nonmathematicians. “Isn’t that an oxymoron? Bluffing is psy- chological,” they might say, or, “Bluffing doesn’t work in online poker.
    [Show full text]
  • Poker 101 Poker Rules and Concepts for Our Annual Charity Tournament
    Poker 101 Poker Rules and Concepts for our Annual Charity Tournament Adapted from MIT 15.S50 Lecture Brainteasers Problem: • (1) In Poker, what is the best hand to go up against Pocket Aces? (other than the other two Aces?) • (2) The situation: heads up on the turn, but before the river comes out you already know you are guaranteed to lose, regardless of what your opponent has. What are your hole cards, and what is on the board? Brainteaser Solution: • (1) In Poker, what is the best hand to go up against Pocket Aces? (other than the other two Aces?) • AA 77.50% 65s 22.50% • (2) The situation: heads up on the turn, but before the river comes out you already know you are guaranteed to lose, regardless of what your opponent has. What are your hole cards, and what is on the board? • Your hole cards: 22 • Board: any quads (5555) Announcements • Annual Charity Poker Tournament – Saturday, 4/15 • Pitch Perfect: A QFS-USWIB Production • Pitch Workshops: 4/11 and 4/18 at 6:30pm • Deadline: 4/18 • Competition: 4/20 • Registration: http://tinyurl.com/qfsuswib • If you are interested but don’t have a team, email us! Poker Rules Texas Hold ‘Em Overview • Texas Hold'em is a community card poker game, with game play focused as much on the betting as on the cards being played • Texas Holdem is played on a single table with 2 to 9 players • You win a pot by having the best hand, or by having all other players fold before the showdown • The structure of Texas Hold'em can be broken up into three main divisions: 1.
    [Show full text]