Like any casino game—does not matter if it is online or not—blackjack is constructed so that the house starts off with the edge. While the 3-2 payout helps to boost the player’s online blackjack odds, the game has two aspects that feed into the house’s edge more naturally than rules that favor the house.
Those two aspects are playing out your hand before the dealer and busting. And they can go hand in hand really.
Let’s look at an ordinary game of online blackjack. It is just you and the dealer. You are dealt your two cards and the dealer has an up card and a hole card. Once the cards are dealt you must play out your hand before the game can continue. There is no way around it.
I know, this seems so trivial. How can playing out your hand first impact your online blackjack odds?
Well, let’s say that you hit and hit again and wind up busting. At that point your wager, your money, belong to the house. And it does not matter whether or not the dealer busts. In fact, the dealer can bust when playing out its hand after you have already busted and your money will still be collected for the house.
And that is the disadvantage of playing out your hand first. And because you are playing first and could lose your money before the dealer plays out its hand, it is considered a disadvantage. Disadvantages are what lower the player’s blackjack odds, while advantages, such as doubling down, increase the player’s odds.
In a way you could consider playing first the trade-off to receiving 3-2 on a natural blackjack. But then that really is not that fair of a trade since you play first in every game while you do not receive a 3-2 payout in every game. And that is why playing first and busting feed into the house’s odds.