Estimating the Number of Decks

Remaining in the Shoe

If you are playing a shoe game, you will have to estimate the number of decks in the discard tray to find the number of decks remaining in the shoe.  Most shoes are designed to prevent your seeing the cards well enough to estimate how many decks remain.  The player has to work backwards to acquire that number.  As always, estimating the number of decks that have been played is a skill which has to be practiced.  Once you are good at estimating, the rest is easy.

You should always know how many decks you are playing.  If you are unsure, ask the dealer.  Once this is known, subtract the number of decks in the discard tray from the total number of decks to get the number of decks remaining in the shoe.  This will be the number you will need to convert the running count to the true count.

If you are playing a six deck game and the discard tray shows two decks have been played, there are four decks left in the shoe.  If you are playing a two deck, pitch game, and there is one deck in the discard tray, then the dealer has one deck left in his/her hand.

To learn how to estimate the number of decks, there is only one way to learn – get out some cards.  You want to start by learning how to judge one deck.  Combine about five or six decks for this exercise.  It is unimportant if they are shuffled or not.  Now cut what you think is a deck from the stack.  Once you have your best guess, count the deck you just cut.  Are there 52?  You should practice until there are 52 plus or minus two cards.  Master this, then move on to two decks.  Using the same procedure, try to get 104 cards, plus or minus four cards.

A deck is about 0.6 inches thick.  So, two would be 1.2 inches. After you learn whole decks, learn to cut half decks.  This will be where the measurements are more beneficial.  One and a half decks should be 0.9 inches thick.  Since this is just under an inch, it should be easier to judge than some of the other stacks.  That makes two and a half decks one and a half inches.  Lastly, three and a half decks are 2.1 inches thick, so that also should be easy to judge. If you are playing a six deck game, about four and a half decks is all you will see dealt, so learning more than four decks is unnecessary.

If you have the good fortune to be at third base, you might get away with stacking chips beside the discard tray.  If you can, the height of chips can be used to estimate the number of decks pretty closely.  Five casino chips are one deck thick.  Being prone to obsessive-compulsive behavior, I took calipers to a local casino and five chips measured exactly 0.625 inches thick.  If you want to check your local casino, buy a used deck of their cards in the gift shop, and stack some chips up beside it.  You’ll find I’m pretty close.  Also, remember the base of the discard tray is about two chips thick, so allow for this thickness.

Now, in real life, you are going to look at the discard tray and the stack is going to be in between decks or half decks.  This makes it difficult to be precise.  So, what should you do?  Should you round up or down?  The answer is, it won’t make a big difference, but you should round down to be safe.  By rounding down here, it causes you to round up on the remaining decks in the shoe.  This means you will be dividing the running count by a larger number, and the true count will be slightly underestimated.  If you were to divide the running count by a smaller number, you would overestimate the true count and might be making a mistake in the next bet, or play.  In a six deck game with two and three fourths decks played, and the count at plus six, rounding down to two is correct.  This puts the shoe with four decks, and the count at plus one and a half.  If you round up to three decks, the shoe would have three decks remaining and the true count would be slightly overestimated at plus 2.  You might double your bet at plus two, and not quite have the advantage you think.

Because of this estimation process, some of the precision of counting is lost.  By having an accurate count, you will keep the error to a minimum.  This problem gave rise to unbalanced counts.  As you know, with an unbalanced count, the deck estimation and true count conversion is eliminated.