I know this is an older thread. As a teacher of mathematics, and avid bj player, I thought I might be able to add something.
In the short run, a player's advantage or disadvantange really does not mean a lot. A player using basic strategy and a progression may indeed do quite well. How long could this last? Unknown, no way to answer--- as it relates to any 1 single player. Maybe a few sessions, maybe 100 sessions. Of course, it is more likely every time you play that your fortunes will reverse, but that does not mean that a single player could not accumulate a handsome sum before that reversal occurs. This happens all the time.
Likewise, a counter playing with an advantage could well get his teeth kicked in for a protracted period. The count soars, you push out big bet after big bet, only to suffer loss after loss. Short term variance does not seem that short term when you are down 30 big bets. Just because you have a mathematical advantage does not mean that you will win on any given hand, or any given 50 hands.
New players, take warning. Some counters start playing and have tremendous results after the first 100 hours of play. Positive variance puts them way ahead of the curve and the money is rolling in. However, some counters can start play and experience negative variance...and get their clock cleaned.
In the end, take blackjack for what it is---a gamble. Yes, if you are a proficeint counter you can gamble with a small advantage. However, to be certain that you turn that small advantage into profits is not easy. It usually takes a large time commitment...many, many hours of play. Only those with time, skill, patience, and a well funded bankroll can play with the knowledge that their efforts have a high probability of rewarding them with profits.
Kindest regards to all,