I is for the Illustrious 18



I. Acronym and reference to an American Indian casino.

IC. Acronym for insurance correlation.

IBJ. Acronym for the software program International Blackjack Professional.

ID. Acronym for identification.

identification.  (ID) The legal papers in your wallet or purse that identify who you are.  Examples of identification include driver license, credit cards, birth certificate, social security card, etc.  See false identification.

Illinois.  In 2016, the state of Illinois had 7 casinos with 101 blackjack tables. See riverboat gambling.
[ qfit.com ]

Illinois Rules  Archived Rules

Illustrious 18. Term coined by Donald Schlesinger to refer to the play variations that provide players the most gain from varying from basic strategy. These plays are:


  • Insurance
  • 16 vs 10
  • 15 vs 10
  • 10,10 vs 5
  • 10,10 vs 6
  • 10 vs 10
  • 12 vs 3
  • 12 vs 2
  • 11 vs Ace
  • 9 vs 2
  • 10 vs Ace
  • 9 vs 7
  • 16 vs 9
  • 13 vs 2
  • 12 vs 4
  • 12 vs 5
  • 12 vs 6
  • 13 vs 3

According to Schlesinger, the insurance play alone is worth over 30% of all the gain. The BIG 3, insurance, 16 vs 10 and 15 vs 10, account for nearly 60%. The top 12 plays account for more than 90%. The above study is applicable for a typical 4-deck shoe game using the Hi-Lo system. A different counting system may add or remove a few plays to or from this list.  Most professional players will know a lot more variations than those recommended here. See Fab Four.  See bet variationMORE INFO
[ 9/86 Schlesinger Attacking the Shoe BJF 5 ] [ 88 Griffin Theory of Blackjack 30 ] [ Sum 92 Dalton The Most Important Plays for Card Counters BJR ] [ 97 Schlesinger Blackjack Attack 70 ] [ 888casino.com ]

Multiparameter Blackjack Engine by John ImmingImming, John HAuthor of several outstanding blackjack simulation software programs during the late 1980s / early 1990s, collectively called the Real World Casino.  Imming’s masterpiece of blackjack analysis software was his Universal Blackjack Engine.  Apparently, around 1995, Imming no longer was working on his blackjack software and he dropped mysteriously from the blackjack scene. John…. are you out there?  Let us know!
[ Computer Gambling Forum: Blackjack Compendium ]

YieldEditor note:  It is uncertain if John Imming is still alive.  Research does show (in the Social Security Death Index) a John H. Imming died in 1998, at the age of 82.   Can anyone verify this?

IMP. Acronym for Imming Multi-parameter.  See below.

IMP-76. {CS} A reference to John Imming’s count (Hi-Opt II) that includes an adjustment for sevens and sixes.  It was Imming’s belief that “The 7 is King!” when it came to playing strategy.  He recommended that (in single and double deck games) you should side-count the 7s first and foremost and, if possible, the 6s next.  See John Imming’s Real World Casino: Multi-parameter Blackjack Engine software in the product review section. 

IMP#-XYZ. {CS} A reference to John Imming’s count (Hi-Opt II) for # number of decks (1 or 2) that includes adjustments for X, Y, and/or Z.  For example, “XYZ” could be “A98”. See above.

Imperial II Count. ??? John Gollehon ??? TBD 

implied count.  An implied count is an educated guess that takes into account what you believe another player is holding for the purpose of playing your hand more accurately.  For example, if the dealer has a small card up, and two players on your right don’t bust after being hit with large cards you can estimate that each of these players have two small or neutral cards in the hole.  An implied count is usually only used in the face-down single deck game. 

in shuffle.  A modified perfect shuffle.   See out shuffle.
[ 03 Poolside The Poolside Report: Blackjack Ace Tracking ]

In BetweenIn BETween. (c2017) A blackjack side bet that pays if the dealer’s up-card falls “between” the player’s initial two cards.  (HA = 5.10% to 10.50%)
[ wizardofodds.com ] [ playags.com ]

independent trials. As in independent trials processes. A mathematical concept that applies to games such as craps and roulette where each play of the game is uninfluenced by past outcomes and, in turn, has no influence on future outcomes. Blackjack is not an independent trials process but rather a dependent trials process. The cards that already have been played do affect the odds on subsequent hands.
[ 66 Thorp Beat the Dealer 42 ] [ 77 Epstein The Theory of Gambling and Statistical Logic Chap 2 ] [ 84 Thorp The Mathematics of Gambling 1 ]

index. 1) The number in the upper left and lower right corners of a playing card, which gives its value. 2) The count or true count necessary to vary from basic strategy and generally expressed as a negative or positive number. (e.g., the Hi-Lo index for a player 16 versus a dealer 10 is 0. Whenever the count is greater than or equal to 0 the player would vary from basic strategy and stand.)  Indexes are used to make better playing decisions based on the count.
2) [ blackjackincolor.com ]

Indian blackjack. At time of writing, there were numerous Indian reservations throughout the United States that offer casino blackjack. Many of these games offer Las Vegas Strip rules with maximum bets of over $1000. Examples include reservations in the following states:

  • Connecticut
  • Florida
  • Michigan
  • Minnesota
  • New York
  • Washington State
  • Wisconsin

[ 9/89 Snyder Blackjack in Michigan BJF ] [ 9/89 Smallwood Blackjack in New York BJF ] [ 10/90 Overhulser Indian BJ in Mich. & Wis. BJC ] [ 12/91 A 14-Day Indian Blackjack Vacation WIN 42 ] [ Win 93, Sum 93 Dalton Blackjack in Michigan BJR ]

Indiana.  In 2016, the state of Indiana had 7 casinos with 210 blackjack tables.
[ qfit.com ]

Indiana Rules  Archived Rules

indice. See index.

Instant 18 BlackjackInstant 18. (c2010) A blackjack side-bet seen at the Station Casinos in Las Vegas.  Player’s make a main bet (like normal) and have the option of a second hand (with the same bet) that will “automatically” be an 18.  (HA ~ 2.04% for the side-bet)
[ discountgambling.net ] [ wizardofodds.com ] [ 888casino.com ]

Insurance Pays 2 to 1

insurance. An optional side bet offered to players by most casinos. The player is betting that the dealer has a 10-valued card down when he shows an ace as an up-card. Players may wager up to half of their original bet to insure their hands against a dealer having a natural. Bets must be placed in the designated area on the layout in front of the players. No money changes hands when the player wins this bet since it pays 2 to 1 unless the player also has a natural. 

Blackjack FAQFrequently Asked Question
When would I ever want to take insurance (or even money)?

Insurance is available when the dealer has an Ace up!Basic strategy for the insurance bet is to never take it. The Hi-Lo count strategy is to take insurance only if the count per deck is greater than 1.5 for single-deck, 2.4 for double-deck and 3 in multi-deck games. As can be seen by the percentages below, insurance is less important to the card counter in multi-deck games than it is in single-deck. In a randomly shuffled 52-card deck the probability of the dealer having a 10 as his hole-card is 16/51 (31.37%). The insurance bet is profitable only if this probability is greater than 33.33%. See call for insurance. See even money.  See insurance line.  See Rules of the Game.

HA (1 Deck) = 5.88%
HA (8 Decks) = 7.47%

[ ARCHIVE: blackjackforumonline.com ] [ 888casino.com ] [12/87 Master Insure a Good Hand BJF 17 ] [ 6/88 Griffin Insure a Good Hand? (Part II) BJF 12 ] [ 6/88 Smallwood Insurance Camouflage BJF 14 ] [ 90 Chambliss Fund. of Blackjack 43 ]

insurance correlation. (IC) A measure of how well a counting system indicates correct insurance betting decisions compared with other systems.  For example, the insurance correlation for the Hi-Lo card counting system is 0.7601.  See playing efficiency. See betting correlation.  See card counting system comparisons.
[ qfit.com ] [ blackjackinfo.com ]

insurance counter. {CS}. A player who is using a special count designed to signal the insurance decision more accurately than a normal card count would. This counter is usually not playing but only giving signals to a seated player.  See insurance.

insurance line. The area of a blackjack table layout on which the insurance bet is placed.   See insurance.

integrity. {RWC} Described in some sources as a measure of the quality of a game in progress. Good integrity is often associated with things happening the way the probabilities of the game say they should be happening. Bad integrity is just the opposite. The BIAS Barometer method claim the ability to quantify this factor. See TARGET.
[ 85 Patterson TARGET Manual 6 ]

IOU. See marker.

Iowa In 2016, the state of Iowa had 19 casinos with 227 blackjack tables. See riverboat gambling.
[ qfit.com ]

Iowa Rules  Archived Rules

IRC. 1) Acronym for initial running count. 2) Acronym for Internet Relay Chat, a commercially free chat program.David Irvine

Irvine, David.  aka Mr. J. A former member of the MIT Blackjack Team in the 1990s and co-founder of the Blackjack Institute. After MIT, David Irvine earned a masters degree in biological engineering from Cornell and an MBA from Purdue University’s Krannert School of Management. He also owns a successful engineering consulting company. See Griffin Investigations.
[ ARCHIVE: blackjackinstitute.com ] [ WIKIPEDIA ] [ ARCHIVE: blackjackscience.com ]

Ita Count. See Green Fountain count.

Ita, Koko. Author of the book 21 Counting Methods to Beat 21 and developer of the Green Fountain count.


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