When you play on online Blackjack, you’re playing an online game with one of the smallest house edges in online gambling! The house edge is only 0.5%-1% for almost all of the different variations, and that’s when you’re playing with just a basic strategy. If you play with a well thought out and proven strategy, which optimizes how you play your hands, then you’re going to be reducing that house edge even lower.
The thing you’ve got to remember here is that it’s not just about you figuring out when you should stand and when you should hit. Whenever you split, double down or wager on any sort of side bet you can be affecting the odds and payout percentages. Other things which can affect it are things such as the number of decks in play and various other rules that are applicable to different Blackjack styles.