half the cards in the PZ. But the 78-card PZ has 39 other cards mixed in. We cannot assume that those 39 cards have a running count of zero. They come from the 273 cards not in the Track Zone. We know that those 273 cards have a count that is the opposite of the TZ. In the simple example, we had complete information about the one-deck PZ and therefore could play as if we were playing a one-deck game. In this example, we have partial information about 1½ decks. Therefore, we have more information than we would have for the full six decks, but less information than if we had complete knowledge of 1½ decks. This is where NRS comes in. The NRS formulae give us a compromise — a virtual shoe size between 1½ and 6 and an adjustment to the initial running count that allows us to estimate the true count in the Play Zone. In this case, there are 2.5 pseudo-decks (actually 2.65, but we can round) and a multiplier of -1.5 times the Track Zone count to get the Initial Running Count. So, if we have Track Zone with a count of -10, our IRC is -1.5 times 10, for 15. At the start of the shoe, the TC is 15 divided by 2.5 remaining pseudo-decks for +6. As we continue through the PZ, the number of pseudo-decks remaining drops from 2.5 down to 1 at the end of the PZ. Then we subtract out the 15 IRC and revert back to standard true count calculation.

As I said, I will not explain here why NRS comes up with these particular numbers. This is not meant to be a math text. You can find that at the reference earlier in the chapter. Instead, I will give three examples using the free NRS Calculator based on the shuffle in the Shuffle Mapping section.

 © 2009 Norman Wattenberger