The longer you play a game with "negative expectation",
such as Blackjack with Basic Strategy, the greater your chances of losing.
IF you really want to maximize your chances of winning
bet 1/2 of all of the money you are wiling to lose
on one hand. Split or Double Down if called for.
If you win, QUIT.
Ditto if you LOSE.
This way your chance of winning is around 48%
and that is as good as you can possibly expect.
This is not a joke.
The real edge that a casino has over you is that they have a near infinite bankroll
and you don't; and, in effect, their time is virtually infinite as well.
Your mathematical expectation is, over time, on average,
to lose a little bit of money with every hand played.
That is why the casinos will comp' you to keep you at the tables.