I am not proficient as a card counter but have read literally all the methodologies employed. The POSITIVE count you speak of is derived by the remaining high cards left in the deck. The 4-FIVES that left the deck means that you have four less low cards and therefore a POSITIVE high card count of PLUS 4. The more high cards left in the deck the higher the POSITIVE count. This favors the player because you have a chance at twenty or twenty-one with a greateer proportion of high cards left. Of course, the fly in the ointment is: so does the dealer (house). But you attempt to increase your bet when the count is higher, POSITIVE, because you do have a better chance at a stronger hand even if the dealer does as well. I have counted, not well, over the years, and the results are minimal unless you play an awful lot. The count doesn't vary dramatically often enough for the average player.