One of the most important things that blackjack players need to do is define their betting limits. After all, nobody wants to fall for the beginner's mistake of overbetting because it can be a bankroll management disaster. That said, let's take a look at some important factors for players to look at when thinking about the perfect bet sizes.
How Long do you want to play?
When deciding your optimal blackjack betting limits, it's important to think about how long you want to play. Sure having 20 total betting units is enough to get you by for one session, but what if you want to keep playing blackjack for 10 sessions of five hours each? This is obvious going to take a lot larger bankroll.
Doing the Math
Let's look at the aforementioned scenario where you want to play 10 sessions of five hours (50 hours total). Also, let's say you have $1,000 to play with; this would give you $20 to lose per hour (1,000/20). If you were playing 75 hands per hour, you could afford to lose around $0.27 per hand (20/75).
To make things easy mathematically, we'll just assume that you're surrendering about a 1% advantage to the house. This being the case, you could theoretically bet $27 per hand (0.27/0.01) - provided everything worked out perfectly according to math. However, as we know, things don't always work out so cleanly in blackjack games.
Accounting for Variance
No simple math can tell you exactly what the future holds for you in blackjack. In fact, the positive variance that occurs in blackjack games is what gives players hope that they can overcome the small house edge and win profits. However, you also have to account for possible negative variance, which could disrupt your betting plan.
As we said before, the math says you could bet $27 a hand; however, to be safe, you'd want to drop your average bet to at least $25 - probably lower to ensure that you last 10, five-hour sessions. In any case, you can see that it's not overly-difficult to come up with a betting plan in blackjack, and it only takes a few moments of your time.