Unlike stock market or sports gambling where betselection/pick is much more important than anything else, a casino game is far more balanced. It has a fixed house edge, fix payouts and fix probability.
Everybody knows of the house edge that lies in a calculation done to favor the casino with offering a lesser payout than the odds. This is done to ensure losses in the long run on certain premises. If I play simple coin flipping with a friend of mine with a condition to pay him a profit of 0.95 for a bet of 1.00 and to take his 1.00 when he loses, given enough trials he will lose. If I do this to 100s of my friends I will have to go rich gradually, even if a few friends somehow manage to get a net win from me. Say they win and lose equal number of times, I will be winning 0.025 for every 1 unit bet placed, averagely. Hence, if a player has 100 units with him, he should lose it all by 4000th bet. It is also known as Average Daily Theoretical loss, also known as ADT, theoretical loss, or "theo" for short. The theoretical loss is the amount of money a player is expected to lose based on the long run statistical advantage the casino has on the particular game being played.
Now my question.
Have you ever seen someone playing with 100 chips and taking 4000 bets to lose that all? Usually people do not play flat or even if they do, they run out at losing a considerable sum in bad streak or winning a considerable sum in good streak. An average player plays not more than 100 trials in a real casino, in any given day and concludes his wins/losses of the day. This is about clever players. Rookies come, buy and lose all before leaving for home. If they buy 100 units, do they take 4000 bets to lose that? Never.
They plan a game for short run, either use multiple bets together(like side bets in baccarat or inside bets on roulette) to lose faster in a little bad streak and in avenging those losses lose the rest even faster, or they use silly progressions to win back faster and ultimately lose all.