There is no reason to stop you, taken you know and can play Basic Strategy backwards flawlessly, have the ability to count a deck down in roughly 25 seconds using a counting method, and know 12 or more Advanced Strategies to increase your odds against the online casinos.
Confident about your playing ability and have no problem with the requirement listed above - you are on your way - YOU ARE A PROFESSIONAL BLACKJACK PLAYER already. People require 3 very important things before they will be persuaded to becoming a full time professional player - family, security, and finance. In fact these 3 factors will influence any person in any major job decision they take through their life, oh .... and .... where they live! Living in Las Vegas or Nevada is not quite your family neighborhood!
The lifestyle of a professional gambler could also not be to the players' liking - nor to his family's and he may lose more than just his money in the end. They must also remember that Blackjack does not come with full medical or unemployment insurance, and that his finance might not be large enough to cover a long run of losses, or to make the big bets needed to get the big one! It is a big decision, as changing any job should be, maybe it can be taken slowly?
What if the player could make some sort of achievable goal during the time he still ahs that stable job, family, security, and extra cash to play with? If a player has "professional Blackjack" skills, why not let it work for him?
For example: A part time player has a day job making just under $ 100 / day. He keeps records his play at the tables and has a win: loss ratio of about 5: 1, (5 wins out of 6 times). He wins on average 6 units of his smallest wager / hour. So ...., if the table minimum is $ 5 and he places bets of between $ 5 - $ 25, he normally takes in roughly $ 30 / hour. Sometimes he wins more and sometimes has also lost $ 300, but consistency will extremely pay off.
If a player wants to average wins of $ 100 / playing session, the same amount equal to his daily earned after tax income. Taking the win: loss ratio of 5: 1, and a implementing a stop-loss set at $ 100, this means he had to win $ 120 5 x to cover for a loss of $ 100 on the 6th session. The players' stop-loss is set at $ 100 (daily work rate and maximum amount he can afford to lose). Each playing session would be treated as if it was a day at work, so ... off days would simply be breaking even. Although the game of Blackjack is win some, lose some, a player can effectively double his income per day.
Any good player keeping records can come up with a similar plan or system - if he earns $ 50 a day and wins 2 out of 3 times, he can set a stop loss of $ 50 and aim to win $ 75 every time he plays.
The system can help players contemplating the move to professional, see that the income can remain the same or even be better than their current income at their present "jobs". They can prove it to themselves and ... become profit from playing blackjack. This system will show players what they are capable of, over a period as long as they want, until they feel comfortable to make the move.
Players who make the move to Professional must also realize that this play is a long term game, and not short term as played before. Basic playing principles much the same: small wager with a Count of +1 and larger wagers above it. This strategy is a "slowly slow" strategy that makes most Counters their money (% advantage x size of bankroll). There are players who no bankroll, and only their table betting to play with. Here a conservative approach must be used to remove corruption from the game.
Some players (Counters) use Jerry Patterson's "Takenown" strategy. Jerry is the Father of "Alternative Blackjack" with his allegations of biases and strings of small and large cards due to shuffling and card pick-up routines. He explains why and how counters can avoid being 'caught' by betting large amounts as the count rises. "Takedown" is a method of betting for non-counters and Jerry explains that players should bet as the count drops, not as it rises, as it is now that the 10s are coming out.
Most successful Counters use a bankroll and increase their advantage when placing each wager based on the count, and end up learning more money long term, riding out the swings of the game. One such swing can result in a player quitting Blackjack play all together, usually having lost all his money. 6 and 8 deck games are the hardest to beat due to shuffling biases, which is hard to prove mathematically. Traditional Patterson betting strategies are more effective against one and two deck games, which are still common in Las Vegas.
Jerry in "Takedown" also recommends that players lock up their winnings and play on to other limits. ie a player must set a goal of say $ 150 for the day, but if he needs to bet out of his $ 120 win, he must not. If he got to $ 150, same deal. Jerry calls this a "winlock" and explains that players must divide their winnings into 3 piles.
Using the above example, the player pockets his $ 120 and place his $ 30 win in 3 piles, two $ 5 chips each. He will place bets from 1 pile only. For the next hand he places a 1 chip bet from pile # 3. If he loses, he bets the last chip from pile # 3. If he lose, he is done for the day. If the player however gets on a winning streak he renews pile # 3 back to 2 units. He then places the next win on pile # 1, then pile # 2, and finally to pile # 3, the betting pile. He might get these 3 piles up to 8 units each, then hit a losing streak and lose pile # 3, then it is time to QUIT. This is an excellent way to maximize your winnings and minimize your loses.