On page 200 of BJA3: "After the first hand is dealt to two players, on average, about eight cards will have been used. Since 13 cards constitute a quarter-deck, when we go to estimate the true count at the start of the second hand, we'll be dividing our running count by three-quarters."

Why does the book suggest to divide by 3/4 deck when there are 8 cards(not equal or greater than 13 cards) being used?
If I round up the remaining deck estimation to quarter-decks:
When there are 40-52 cards left, I divide by 1 deck.
When there are 27-39 cards left, I divide by 3/4 deck.
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