statistical edge
Everything depends on the length of time you play (the number of hands). The larger the number, the more likely it is that the results will approximate the distribution in the normal population. That is the "statistical edge." If you play 10,000 hands over some period of time, it is likely that the results of those hands will approximate statistical averages.
In plain English, if you are a full-time counter, or play with a team, and you are playing 300-500 hands a day, day in and day out, the results will approximate statistical definitions.
Anyone who expects to play a few hundred hands, or to play one weekend a month, or to play occasionally, with some type of statistical advantage fails to understand the basic theories of blackjack.
The specific logical fallacy involved is what Tversky and Kahneman called the Law of Small Numbers--the common (and totally incorrect) belief that a small series of events will perfectly represent the normal distribution of a much larger series of events.
If you want to make money playing blackjack, that isn't too hard. I strongly suggest that your first step should be rooting out the logical fallacies that keep most wannabe counters too poor to do anything meaningful at the tables. The most harmful fallacy for beginning counters is that small series events exactly replicate the population of all events. They do not.
The ONLY way you can gain a "statistical edge" in blackjack is to play a LOT. The more hands you play, the more the results will approximate the distribution of events in the population. If you are playing less than 2000 hands a week, the results can be up, down, or right in the middle; the "statistical edge" absolutely, positively does not apply to 50-100 hands played once a week.
If you believe that every series of blackjack hands represents a perfectly representative slice of "all blackjack hands," you need to do some serious homework before you toss your chips on the table. For starters, read "Decision Traps: The Ten Barriers To Brilliant Decision Making And How To Overcome Them," by Russo and Schoemaker. Not someday, or when you have time--BEFORE YOU PLAY ANOTHER HAND OF BLACKJACK.
I have done this for a long time, and I have done it successfully. I can tell you quite clearly that anyone who believes that a "statistical advantage" can be leveraged in a few hundred hands played on a sojourn to the nearby casino once a month fails to understand both statistics and fundamental blackjack theory. It is a myth, and a very costly one. The sooner you accept that, the sooner you can start making money playing blackjack.
Good Luck